1tsq - Revision history

OCA at 06:33, 23 August 2023

OCA — Wed, 23 Aug 2023 06:33:32 GMT

←Older revision		Revision as of 06:33, 23 August 2023
Line 3:		Line 3:
	<StructureSection load='1tsq' size='340' side='right'caption='[[1tsq]], [[Resolution\|resolution]] 2.00Å' scene=''>		<StructureSection load='1tsq' size='340' side='right'caption='[[1tsq]], [[Resolution\|resolution]] 2.00Å' scene=''>
	== Structural highlights ==		== Structural highlights ==
-	<table><tr><td colspan='2'>[[1tsq]] is a 3 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TSQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1TSQ FirstGlance]. <br>	+	<table><tr><td colspan='2'>[[1tsq]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/HIV-1_M:B_ARV2/SF2 HIV-1 M:B_ARV2/SF2] and [https://en.wikipedia.org/wiki/HIV-1_M:B_HXB2R HIV-1 M:B_HXB2R]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TSQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1TSQ FirstGlance]. <br>
-	</td></tr><tr id='~~ligand~~'><td class="sblockLbl"><b>[[~~Ligand~~\|~~Ligands~~:]]</b></td><td class="sblockDat" id="~~ligandDat~~">~~<scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene>~~</td></tr>	+	</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models\|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution\|Resolution]] 2Å</td></tr>
-	<tr id='~~activity~~'><td class="sblockLbl"><b>~~Activity~~:</b></td><td class="sblockDat"><~~span class~~='~~plainlinks~~'>~~[https://en.wikipedia.org/wiki/HIV-1_retropepsin HIV-1 retropepsin], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.23.16 3.4.23.16]~~ </~~span~~></td></tr>	+	<tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene></td></tr>
	<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1tsq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1tsq OCA], [https://pdbe.org/1tsq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1tsq RCSB], [https://www.ebi.ac.uk/pdbsum/1tsq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1tsq ProSAT]</span></td></tr>		<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1tsq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1tsq OCA], [https://pdbe.org/1tsq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1tsq RCSB], [https://www.ebi.ac.uk/pdbsum/1tsq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1tsq ProSAT]</span></td></tr>
	</table>		</table>
	== Function ==		== Function ==
-	[[https://www.uniprot.org/uniprot/POL_HV1A2 POL_HV1A2]] Gag-Pol polyprotein and Gag polyprotein may regulate their own translation, by the binding genomic RNA in the 5'-UTR. At low concentration, Gag-Pol and Gag would promote translation, whereas at high concentration, the polyproteins encapsidate genomic RNA and then shutt off translation (By similarity). Matrix protein p17 has two main functions: in infected cell, it targets Gag and Gag-pol polyproteins to the plasma membrane via a multipartite membrane-binding signal, that includes its myristoylated N-terminus. The second function is to play a role in nuclear localization of the viral genome at the very start of cell infection. Matrix protein is the part of the pre-integration complex. It binds in the cytoplasm the human BAF protein which prevent autointegration of the viral genome, and might be included in virions at the ration of zero to 3 BAF dimer per virion. The myristoylation signal and the NLS thus exert conflicting influences its subcellular localization. The key regulation of these motifs might be phosphorylation of a portion of MA molecules on the C-terminal tyrosine at the time of virus maturation, by virion-associated cellular tyrosine kinase. Implicated in the release from host cell mediated by Vpu (By similarity). Capsid protein p24 forms the conical core that encapsulates the genomic RNA-nucleocapsid complex in the virion. Most core are conical, with only 7% tubular. The core is constituted by capsid protein hexamer subunits. The core is disassembled soon after virion entry. Interaction with human PPIA/CYPA protects the virus from restriction by human TRIM5-alpha and from an unknown antiviral activity in human cells. This capsid restriction by TRIM5 is one of the factors which restricts HIV-1 to the human species (By similarity). Nucleocapsid protein p7 encapsulates and protects viral dimeric unspliced (genomic) RNA. Binds these RNAs through its zinc fingers. Facilitates rearangement of nucleic acid secondary structure during retrotranscription of genomic RNA. This capability is referred to as nucleic acid chaperone activity (By similarity). The aspartyl protease mediates proteolytic cleavages of Gag and Gag-Pol polyproteins during or shortly after the release of the virion from the plasma membrane. Cleavages take place as an ordered, step-wise cascade to yield mature proteins. This process is called maturation. Displays maximal activity during the budding process just prior to particle release from the cell. Also cleaves Nef and Vif, probably concomitantly with viral structural proteins on maturation of virus particles (By similarity). Reverse transcriptase/ribonuclease H (RT) is a multifunctional enzyme that converts the viral RNA genome into dsDNA in the cytoplasm, shortly after virus entry into the cell. This enzyme displays a DNA polymerase activity that can copy either DNA or RNA templates, and a ribonuclease H (RNase H) activity that cleaves the RNA strand of RNA-DNA heteroduplexes in a partially processive 3' to 5' endonucleasic mode. Conversion of viral genomic RNA into dsDNA requires many steps. A tRNA(3)-Lys binds to the primer-binding site (PBS) situated at the 5'-end of the viral RNA. RT uses the 3' end of the tRNA primer to perform a short round of RNA-dependent minus-strand DNA synthesis. The reading proceeds through the U5 region and ends after the repeated (R) region which is present at both ends of viral RNA. The portion of the RNA-DNA heteroduplex is digested by the RNase H, resulting in a ssDNA product attached to the tRNA primer. This ssDNA/tRNA hybridizes with the identical R region situated at the 3' end of viral RNA. This template exchange, known as minus-strand DNA strong stop transfer, can be either intra- or intermolecular. RT uses the 3' end of this newly synthesized short ssDNA to perform the RNA-dependent minus-strand DNA synthesis of the whole template. RNase H digests the RNA template except for two polypurine tracts (PPTs) situated at the 5'-end and near the center of the genome. It is not clear if both polymerase and RNase H activities are simultaneous. RNase H probably can proceed both in a polymerase-dependent (RNA cut into small fragments by the same RT performing DNA synthesis) and a polymerase-independent mode (cleavage of remaining RNA fragments by free RTs). Secondly, RT performs DNA-directed plus-strand DNA synthesis using the PPTs that have not been removed by RNase H as primers. PPTs and tRNA primers are then removed by RNase H. The 3' and 5' ssDNA PBS regions hybridize to form a circular dsDNA intermediate. Strand displacement synthesis by RT to the PBS and PPT ends produces a blunt ended, linear dsDNA copy of the viral genome that includes long terminal repeats (LTRs) at both ends (By similarity). Integrase catalyzes viral DNA integration into the host chromosome, by performing a series of DNA cutting and joining reactions. This enzyme activity takes place after virion entry into a cell and reverse transcription of the RNA genome in dsDNA. The first step in the integration process is 3' processing. This step requires a complex comprising the viral genome, matrix protein, Vpr and integrase. This complex is called the pre-integration complex (PIC). The integrase protein removes 2 nucleotides from each 3' end of the viral DNA, leaving recessed CA OH's at the 3' ends. In the second step, the PIC enters cell nucleus. This process is mediated through integrase and Vpr proteins, and allows the virus to infect a non dividing cell. This ability to enter the nucleus is specific of lentiviruses, other retroviruses cannot and rely on cell division to access cell chromosomes. In the third step, termed strand transfer, the integrase protein joins the previously processed 3' ends to the 5' ends of strands of target cellular DNA at the site of integration. The 5'-ends are produced by integrase-catalyzed staggered cuts, 5 bp apart. A Y-shaped, gapped, recombination intermediate results, with the 5'-ends of the viral DNA strands and the 3' ends of target DNA strands remaining unjoined, flanking a gap of 5 bp. The last step is viral DNA integration into host chromosome. This involves host DNA repair synthesis in which the 5 bp gaps between the unjoined strands are filled in and then ligated. Since this process occurs at both cuts flanking the HIV genome, a 5 bp duplication of host DNA is produced at the ends of HIV-1 integration. Alternatively, Integrase may catalyze the excision of viral DNA just after strand transfer, this is termed disintegration (By similarity). [[https://www.uniprot.org/uniprot/GAG_HV1H2 GAG_HV1H2]] Matrix protein p17 targets Gag and Gag-Pol polyproteins to the plasma membrane via a multipartite membrane binding signal, that includes its myristoylated N-terminus. Also mediates nuclear localization of the preintegration complex. Implicated in the release from host cell mediated by Vpu. Capsid protein p24 forms the conical core of the virus that encapsulates the genomic RNA-nucleocapsid complex. Nucleocapsid protein p7 encapsulates and protects viral dimeric unspliced (genomic) RNA. Binds these RNAs through its zinc fingers. p6-gag plays a role in budding of the assembled particle by interacting with the host class E VPS proteins TSG101 and PDCD6IP/AIP1 (By similarity).	+	[https://www.uniprot.org/uniprot/POL_HV1A2 POL_HV1A2] Gag-Pol polyprotein and Gag polyprotein may regulate their own translation, by the binding genomic RNA in the 5'-UTR. At low concentration, Gag-Pol and Gag would promote translation, whereas at high concentration, the polyproteins encapsidate genomic RNA and then shutt off translation (By similarity). Matrix protein p17 has two main functions: in infected cell, it targets Gag and Gag-pol polyproteins to the plasma membrane via a multipartite membrane-binding signal, that includes its myristoylated N-terminus. The second function is to play a role in nuclear localization of the viral genome at the very start of cell infection. Matrix protein is the part of the pre-integration complex. It binds in the cytoplasm the human BAF protein which prevent autointegration of the viral genome, and might be included in virions at the ration of zero to 3 BAF dimer per virion. The myristoylation signal and the NLS thus exert conflicting influences its subcellular localization. The key regulation of these motifs might be phosphorylation of a portion of MA molecules on the C-terminal tyrosine at the time of virus maturation, by virion-associated cellular tyrosine kinase. Implicated in the release from host cell mediated by Vpu (By similarity). Capsid protein p24 forms the conical core that encapsulates the genomic RNA-nucleocapsid complex in the virion. Most core are conical, with only 7% tubular. The core is constituted by capsid protein hexamer subunits. The core is disassembled soon after virion entry. Interaction with human PPIA/CYPA protects the virus from restriction by human TRIM5-alpha and from an unknown antiviral activity in human cells. This capsid restriction by TRIM5 is one of the factors which restricts HIV-1 to the human species (By similarity). Nucleocapsid protein p7 encapsulates and protects viral dimeric unspliced (genomic) RNA. Binds these RNAs through its zinc fingers. Facilitates rearangement of nucleic acid secondary structure during retrotranscription of genomic RNA. This capability is referred to as nucleic acid chaperone activity (By similarity). The aspartyl protease mediates proteolytic cleavages of Gag and Gag-Pol polyproteins during or shortly after the release of the virion from the plasma membrane. Cleavages take place as an ordered, step-wise cascade to yield mature proteins. This process is called maturation. Displays maximal activity during the budding process just prior to particle release from the cell. Also cleaves Nef and Vif, probably concomitantly with viral structural proteins on maturation of virus particles (By similarity). Reverse transcriptase/ribonuclease H (RT) is a multifunctional enzyme that converts the viral RNA genome into dsDNA in the cytoplasm, shortly after virus entry into the cell. This enzyme displays a DNA polymerase activity that can copy either DNA or RNA templates, and a ribonuclease H (RNase H) activity that cleaves the RNA strand of RNA-DNA heteroduplexes in a partially processive 3' to 5' endonucleasic mode. Conversion of viral genomic RNA into dsDNA requires many steps. A tRNA(3)-Lys binds to the primer-binding site (PBS) situated at the 5'-end of the viral RNA. RT uses the 3' end of the tRNA primer to perform a short round of RNA-dependent minus-strand DNA synthesis. The reading proceeds through the U5 region and ends after the repeated (R) region which is present at both ends of viral RNA. The portion of the RNA-DNA heteroduplex is digested by the RNase H, resulting in a ssDNA product attached to the tRNA primer. This ssDNA/tRNA hybridizes with the identical R region situated at the 3' end of viral RNA. This template exchange, known as minus-strand DNA strong stop transfer, can be either intra- or intermolecular. RT uses the 3' end of this newly synthesized short ssDNA to perform the RNA-dependent minus-strand DNA synthesis of the whole template. RNase H digests the RNA template except for two polypurine tracts (PPTs) situated at the 5'-end and near the center of the genome. It is not clear if both polymerase and RNase H activities are simultaneous. RNase H probably can proceed both in a polymerase-dependent (RNA cut into small fragments by the same RT performing DNA synthesis) and a polymerase-independent mode (cleavage of remaining RNA fragments by free RTs). Secondly, RT performs DNA-directed plus-strand DNA synthesis using the PPTs that have not been removed by RNase H as primers. PPTs and tRNA primers are then removed by RNase H. The 3' and 5' ssDNA PBS regions hybridize to form a circular dsDNA intermediate. Strand displacement synthesis by RT to the PBS and PPT ends produces a blunt ended, linear dsDNA copy of the viral genome that includes long terminal repeats (LTRs) at both ends (By similarity). Integrase catalyzes viral DNA integration into the host chromosome, by performing a series of DNA cutting and joining reactions. This enzyme activity takes place after virion entry into a cell and reverse transcription of the RNA genome in dsDNA. The first step in the integration process is 3' processing. This step requires a complex comprising the viral genome, matrix protein, Vpr and integrase. This complex is called the pre-integration complex (PIC). The integrase protein removes 2 nucleotides from each 3' end of the viral DNA, leaving recessed CA OH's at the 3' ends. In the second step, the PIC enters cell nucleus. This process is mediated through integrase and Vpr proteins, and allows the virus to infect a non dividing cell. This ability to enter the nucleus is specific of lentiviruses, other retroviruses cannot and rely on cell division to access cell chromosomes. In the third step, termed strand transfer, the integrase protein joins the previously processed 3' ends to the 5' ends of strands of target cellular DNA at the site of integration. The 5'-ends are produced by integrase-catalyzed staggered cuts, 5 bp apart. A Y-shaped, gapped, recombination intermediate results, with the 5'-ends of the viral DNA strands and the 3' ends of target DNA strands remaining unjoined, flanking a gap of 5 bp. The last step is viral DNA integration into host chromosome. This involves host DNA repair synthesis in which the 5 bp gaps between the unjoined strands are filled in and then ligated. Since this process occurs at both cuts flanking the HIV genome, a 5 bp duplication of host DNA is produced at the ends of HIV-1 integration. Alternatively, Integrase may catalyze the excision of viral DNA just after strand transfer, this is termed disintegration (By similarity).
	== Evolutionary Conservation ==		== Evolutionary Conservation ==
	[[Image:Consurf_key_small.gif\|200px\|right]]		[[Image:Consurf_key_small.gif\|200px\|right]]
Line 36:		Line 36:
	__TOC__		__TOC__
	</StructureSection>		</StructureSection>
-	[[Category: HIV-1 ~~retropepsin~~]]	+	[[Category: HIV-1 M:B_ARV2/SF2]]
		+	[[Category: HIV-1 M:B_HXB2R]]
	[[Category: Large Structures]]		[[Category: Large Structures]]
-	[[Category: King~~, N M~~]]	+	[[Category: King NM]]
-	[[Category: Nalivaika~~, E A~~]]	+	[[Category: Nalivaika EA]]
-	[[Category: Prabu-Jeyabalan, M]]	+	[[Category: Prabu-Jeyabalan M]]
-	[[Category: Schiffer~~, C A]]~~	+	[[Category: Schiffer CA]]
-	~~[[Category: Co-evolution]]~~	+
-	~~[[Category: Hiv-1 protease]]~~	+
-	~~[[Category: Hydrolase-viral protein complex]]~~	+
-	~~[[Category: Nucleocapdi]]~~	+
-	~~[[Category: Substrate recognition~~]]	+

OCA at 06:04, 28 April 2021

OCA — Wed, 28 Apr 2021 06:04:33 GMT

←Older revision		Revision as of 06:04, 28 April 2021
Line 3:		Line 3:
	<StructureSection load='1tsq' size='340' side='right'caption='[[1tsq]], [[Resolution\|resolution]] 2.00Å' scene=''>		<StructureSection load='1tsq' size='340' side='right'caption='[[1tsq]], [[Resolution\|resolution]] 2.00Å' scene=''>
	== Structural highlights ==		== Structural highlights ==
-	<table><tr><td colspan='2'>[[1tsq]] is a 3 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TSQ OCA]. For a <b>guided tour on the structure components</b> use [~~http~~://~~oca~~.~~weizmann.ac.il/oca-docs~~/fgij/fg.htm?mol=1TSQ FirstGlance]. <br>	+	<table><tr><td colspan='2'>[[1tsq]] is a 3 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TSQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1TSQ FirstGlance]. <br>
-	</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene></td></tr>	+	</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene></td></tr>
-	<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[~~http~~://en.wikipedia.org/wiki/HIV-1_retropepsin HIV-1 retropepsin], with EC number [~~http~~://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.23.16 3.4.23.16] </span></td></tr>	+	<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/HIV-1_retropepsin HIV-1 retropepsin], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.23.16 3.4.23.16] </span></td></tr>
-	<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[~~http~~://~~oca~~.~~weizmann.ac.il/oca-docs~~/fgij/fg.htm?mol=1tsq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1tsq OCA], [~~http~~://pdbe.org/1tsq PDBe], [~~http~~://www.rcsb.org/pdb/explore.do?structureId=1tsq RCSB], [~~http~~://www.ebi.ac.uk/pdbsum/1tsq PDBsum], [~~http~~://prosat.h-its.org/prosat/prosatexe?pdbcode=1tsq ProSAT]</span></td></tr>	+	<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1tsq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1tsq OCA], [https://pdbe.org/1tsq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1tsq RCSB], [https://www.ebi.ac.uk/pdbsum/1tsq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1tsq ProSAT]</span></td></tr>
	</table>		</table>
	== Function ==		== Function ==
-	[[~~http~~://www.uniprot.org/uniprot/POL_HV1A2 POL_HV1A2]] Gag-Pol polyprotein and Gag polyprotein may regulate their own translation, by the binding genomic RNA in the 5'-UTR. At low concentration, Gag-Pol and Gag would promote translation, whereas at high concentration, the polyproteins encapsidate genomic RNA and then shutt off translation (By similarity). Matrix protein p17 has two main functions: in infected cell, it targets Gag and Gag-pol polyproteins to the plasma membrane via a multipartite membrane-binding signal, that includes its myristoylated N-terminus. The second function is to play a role in nuclear localization of the viral genome at the very start of cell infection. Matrix protein is the part of the pre-integration complex. It binds in the cytoplasm the human BAF protein which prevent autointegration of the viral genome, and might be included in virions at the ration of zero to 3 BAF dimer per virion. The myristoylation signal and the NLS thus exert conflicting influences its subcellular localization. The key regulation of these motifs might be phosphorylation of a portion of MA molecules on the C-terminal tyrosine at the time of virus maturation, by virion-associated cellular tyrosine kinase. Implicated in the release from host cell mediated by Vpu (By similarity). Capsid protein p24 forms the conical core that encapsulates the genomic RNA-nucleocapsid complex in the virion. Most core are conical, with only 7% tubular. The core is constituted by capsid protein hexamer subunits. The core is disassembled soon after virion entry. Interaction with human PPIA/CYPA protects the virus from restriction by human TRIM5-alpha and from an unknown antiviral activity in human cells. This capsid restriction by TRIM5 is one of the factors which restricts HIV-1 to the human species (By similarity). Nucleocapsid protein p7 encapsulates and protects viral dimeric unspliced (genomic) RNA. Binds these RNAs through its zinc fingers. Facilitates rearangement of nucleic acid secondary structure during retrotranscription of genomic RNA. This capability is referred to as nucleic acid chaperone activity (By similarity). The aspartyl protease mediates proteolytic cleavages of Gag and Gag-Pol polyproteins during or shortly after the release of the virion from the plasma membrane. Cleavages take place as an ordered, step-wise cascade to yield mature proteins. This process is called maturation. Displays maximal activity during the budding process just prior to particle release from the cell. Also cleaves Nef and Vif, probably concomitantly with viral structural proteins on maturation of virus particles (By similarity). Reverse transcriptase/ribonuclease H (RT) is a multifunctional enzyme that converts the viral RNA genome into dsDNA in the cytoplasm, shortly after virus entry into the cell. This enzyme displays a DNA polymerase activity that can copy either DNA or RNA templates, and a ribonuclease H (RNase H) activity that cleaves the RNA strand of RNA-DNA heteroduplexes in a partially processive 3' to 5' endonucleasic mode. Conversion of viral genomic RNA into dsDNA requires many steps. A tRNA(3)-Lys binds to the primer-binding site (PBS) situated at the 5'-end of the viral RNA. RT uses the 3' end of the tRNA primer to perform a short round of RNA-dependent minus-strand DNA synthesis. The reading proceeds through the U5 region and ends after the repeated (R) region which is present at both ends of viral RNA. The portion of the RNA-DNA heteroduplex is digested by the RNase H, resulting in a ssDNA product attached to the tRNA primer. This ssDNA/tRNA hybridizes with the identical R region situated at the 3' end of viral RNA. This template exchange, known as minus-strand DNA strong stop transfer, can be either intra- or intermolecular. RT uses the 3' end of this newly synthesized short ssDNA to perform the RNA-dependent minus-strand DNA synthesis of the whole template. RNase H digests the RNA template except for two polypurine tracts (PPTs) situated at the 5'-end and near the center of the genome. It is not clear if both polymerase and RNase H activities are simultaneous. RNase H probably can proceed both in a polymerase-dependent (RNA cut into small fragments by the same RT performing DNA synthesis) and a polymerase-independent mode (cleavage of remaining RNA fragments by free RTs). Secondly, RT performs DNA-directed plus-strand DNA synthesis using the PPTs that have not been removed by RNase H as primers. PPTs and tRNA primers are then removed by RNase H. The 3' and 5' ssDNA PBS regions hybridize to form a circular dsDNA intermediate. Strand displacement synthesis by RT to the PBS and PPT ends produces a blunt ended, linear dsDNA copy of the viral genome that includes long terminal repeats (LTRs) at both ends (By similarity). Integrase catalyzes viral DNA integration into the host chromosome, by performing a series of DNA cutting and joining reactions. This enzyme activity takes place after virion entry into a cell and reverse transcription of the RNA genome in dsDNA. The first step in the integration process is 3' processing. This step requires a complex comprising the viral genome, matrix protein, Vpr and integrase. This complex is called the pre-integration complex (PIC). The integrase protein removes 2 nucleotides from each 3' end of the viral DNA, leaving recessed CA OH's at the 3' ends. In the second step, the PIC enters cell nucleus. This process is mediated through integrase and Vpr proteins, and allows the virus to infect a non dividing cell. This ability to enter the nucleus is specific of lentiviruses, other retroviruses cannot and rely on cell division to access cell chromosomes. In the third step, termed strand transfer, the integrase protein joins the previously processed 3' ends to the 5' ends of strands of target cellular DNA at the site of integration. The 5'-ends are produced by integrase-catalyzed staggered cuts, 5 bp apart. A Y-shaped, gapped, recombination intermediate results, with the 5'-ends of the viral DNA strands and the 3' ends of target DNA strands remaining unjoined, flanking a gap of 5 bp. The last step is viral DNA integration into host chromosome. This involves host DNA repair synthesis in which the 5 bp gaps between the unjoined strands are filled in and then ligated. Since this process occurs at both cuts flanking the HIV genome, a 5 bp duplication of host DNA is produced at the ends of HIV-1 integration. Alternatively, Integrase may catalyze the excision of viral DNA just after strand transfer, this is termed disintegration (By similarity). [[~~http~~://www.uniprot.org/uniprot/GAG_HV1H2 GAG_HV1H2]] Matrix protein p17 targets Gag and Gag-Pol polyproteins to the plasma membrane via a multipartite membrane binding signal, that includes its myristoylated N-terminus. Also mediates nuclear localization of the preintegration complex. Implicated in the release from host cell mediated by Vpu. Capsid protein p24 forms the conical core of the virus that encapsulates the genomic RNA-nucleocapsid complex. Nucleocapsid protein p7 encapsulates and protects viral dimeric unspliced (genomic) RNA. Binds these RNAs through its zinc fingers. p6-gag plays a role in budding of the assembled particle by interacting with the host class E VPS proteins TSG101 and PDCD6IP/AIP1 (By similarity).	+	[[https://www.uniprot.org/uniprot/POL_HV1A2 POL_HV1A2]] Gag-Pol polyprotein and Gag polyprotein may regulate their own translation, by the binding genomic RNA in the 5'-UTR. At low concentration, Gag-Pol and Gag would promote translation, whereas at high concentration, the polyproteins encapsidate genomic RNA and then shutt off translation (By similarity). Matrix protein p17 has two main functions: in infected cell, it targets Gag and Gag-pol polyproteins to the plasma membrane via a multipartite membrane-binding signal, that includes its myristoylated N-terminus. The second function is to play a role in nuclear localization of the viral genome at the very start of cell infection. Matrix protein is the part of the pre-integration complex. It binds in the cytoplasm the human BAF protein which prevent autointegration of the viral genome, and might be included in virions at the ration of zero to 3 BAF dimer per virion. The myristoylation signal and the NLS thus exert conflicting influences its subcellular localization. The key regulation of these motifs might be phosphorylation of a portion of MA molecules on the C-terminal tyrosine at the time of virus maturation, by virion-associated cellular tyrosine kinase. Implicated in the release from host cell mediated by Vpu (By similarity). Capsid protein p24 forms the conical core that encapsulates the genomic RNA-nucleocapsid complex in the virion. Most core are conical, with only 7% tubular. The core is constituted by capsid protein hexamer subunits. The core is disassembled soon after virion entry. Interaction with human PPIA/CYPA protects the virus from restriction by human TRIM5-alpha and from an unknown antiviral activity in human cells. This capsid restriction by TRIM5 is one of the factors which restricts HIV-1 to the human species (By similarity). Nucleocapsid protein p7 encapsulates and protects viral dimeric unspliced (genomic) RNA. Binds these RNAs through its zinc fingers. Facilitates rearangement of nucleic acid secondary structure during retrotranscription of genomic RNA. This capability is referred to as nucleic acid chaperone activity (By similarity). The aspartyl protease mediates proteolytic cleavages of Gag and Gag-Pol polyproteins during or shortly after the release of the virion from the plasma membrane. Cleavages take place as an ordered, step-wise cascade to yield mature proteins. This process is called maturation. Displays maximal activity during the budding process just prior to particle release from the cell. Also cleaves Nef and Vif, probably concomitantly with viral structural proteins on maturation of virus particles (By similarity). Reverse transcriptase/ribonuclease H (RT) is a multifunctional enzyme that converts the viral RNA genome into dsDNA in the cytoplasm, shortly after virus entry into the cell. This enzyme displays a DNA polymerase activity that can copy either DNA or RNA templates, and a ribonuclease H (RNase H) activity that cleaves the RNA strand of RNA-DNA heteroduplexes in a partially processive 3' to 5' endonucleasic mode. Conversion of viral genomic RNA into dsDNA requires many steps. A tRNA(3)-Lys binds to the primer-binding site (PBS) situated at the 5'-end of the viral RNA. RT uses the 3' end of the tRNA primer to perform a short round of RNA-dependent minus-strand DNA synthesis. The reading proceeds through the U5 region and ends after the repeated (R) region which is present at both ends of viral RNA. The portion of the RNA-DNA heteroduplex is digested by the RNase H, resulting in a ssDNA product attached to the tRNA primer. This ssDNA/tRNA hybridizes with the identical R region situated at the 3' end of viral RNA. This template exchange, known as minus-strand DNA strong stop transfer, can be either intra- or intermolecular. RT uses the 3' end of this newly synthesized short ssDNA to perform the RNA-dependent minus-strand DNA synthesis of the whole template. RNase H digests the RNA template except for two polypurine tracts (PPTs) situated at the 5'-end and near the center of the genome. It is not clear if both polymerase and RNase H activities are simultaneous. RNase H probably can proceed both in a polymerase-dependent (RNA cut into small fragments by the same RT performing DNA synthesis) and a polymerase-independent mode (cleavage of remaining RNA fragments by free RTs). Secondly, RT performs DNA-directed plus-strand DNA synthesis using the PPTs that have not been removed by RNase H as primers. PPTs and tRNA primers are then removed by RNase H. The 3' and 5' ssDNA PBS regions hybridize to form a circular dsDNA intermediate. Strand displacement synthesis by RT to the PBS and PPT ends produces a blunt ended, linear dsDNA copy of the viral genome that includes long terminal repeats (LTRs) at both ends (By similarity). Integrase catalyzes viral DNA integration into the host chromosome, by performing a series of DNA cutting and joining reactions. This enzyme activity takes place after virion entry into a cell and reverse transcription of the RNA genome in dsDNA. The first step in the integration process is 3' processing. This step requires a complex comprising the viral genome, matrix protein, Vpr and integrase. This complex is called the pre-integration complex (PIC). The integrase protein removes 2 nucleotides from each 3' end of the viral DNA, leaving recessed CA OH's at the 3' ends. In the second step, the PIC enters cell nucleus. This process is mediated through integrase and Vpr proteins, and allows the virus to infect a non dividing cell. This ability to enter the nucleus is specific of lentiviruses, other retroviruses cannot and rely on cell division to access cell chromosomes. In the third step, termed strand transfer, the integrase protein joins the previously processed 3' ends to the 5' ends of strands of target cellular DNA at the site of integration. The 5'-ends are produced by integrase-catalyzed staggered cuts, 5 bp apart. A Y-shaped, gapped, recombination intermediate results, with the 5'-ends of the viral DNA strands and the 3' ends of target DNA strands remaining unjoined, flanking a gap of 5 bp. The last step is viral DNA integration into host chromosome. This involves host DNA repair synthesis in which the 5 bp gaps between the unjoined strands are filled in and then ligated. Since this process occurs at both cuts flanking the HIV genome, a 5 bp duplication of host DNA is produced at the ends of HIV-1 integration. Alternatively, Integrase may catalyze the excision of viral DNA just after strand transfer, this is termed disintegration (By similarity). [[https://www.uniprot.org/uniprot/GAG_HV1H2 GAG_HV1H2]] Matrix protein p17 targets Gag and Gag-Pol polyproteins to the plasma membrane via a multipartite membrane binding signal, that includes its myristoylated N-terminus. Also mediates nuclear localization of the preintegration complex. Implicated in the release from host cell mediated by Vpu. Capsid protein p24 forms the conical core of the virus that encapsulates the genomic RNA-nucleocapsid complex. Nucleocapsid protein p7 encapsulates and protects viral dimeric unspliced (genomic) RNA. Binds these RNAs through its zinc fingers. p6-gag plays a role in budding of the assembled particle by interacting with the host class E VPS proteins TSG101 and PDCD6IP/AIP1 (By similarity).
	== Evolutionary Conservation ==		== Evolutionary Conservation ==
	[[Image:Consurf_key_small.gif\|200px\|right]]		[[Image:Consurf_key_small.gif\|200px\|right]]

OCA at 13:18, 17 July 2019

OCA — Wed, 17 Jul 2019 13:18:05 GMT

←Older revision		Revision as of 13:18, 17 July 2019
Line 1:		Line 1:

	==CRYSTAL STRUCTURE OF AP2V SUBSTRATE VARIANT OF NC-P1 DECAMER PEPTIDE IN COMPLEX WITH V82A/D25N HIV-1 PROTEASE MUTANT==		==CRYSTAL STRUCTURE OF AP2V SUBSTRATE VARIANT OF NC-P1 DECAMER PEPTIDE IN COMPLEX WITH V82A/D25N HIV-1 PROTEASE MUTANT==
-	<StructureSection load='1tsq' size='340' side='right' caption='[[1tsq]], [[Resolution\|resolution]] 2.00Å' scene=''>	+	<StructureSection load='1tsq' size='340' side='right'caption='[[1tsq]], [[Resolution\|resolution]] 2.00Å' scene=''>
	== Structural highlights ==		== Structural highlights ==
	<table><tr><td colspan='2'>[[1tsq]] is a 3 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TSQ OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1TSQ FirstGlance]. <br>		<table><tr><td colspan='2'>[[1tsq]] is a 3 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TSQ OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1TSQ FirstGlance]. <br>
Line 14:		Line 14:
	Check<jmol>		Check<jmol>
	<jmolCheckbox>		<jmolCheckbox>
-	<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ts/1tsq_consurf.spt"</scriptWhenChecked>	+	<scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ts/1tsq_consurf.spt"</scriptWhenChecked>
	<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>		<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
	<text>to colour the structure by Evolutionary Conservation</text>		<text>to colour the structure by Evolutionary Conservation</text>
Line 31:		Line 31:

	==See Also==		==See Also==
-	*[[Immunodeficiency virus protease\|Immunodeficiency virus protease]]	+	*[[Immunodeficiency virus protease 3D structures\|Immunodeficiency virus protease 3D structures]]
	== References ==		== References ==
	<references/>		<references/>
Line 37:		Line 37:
	</StructureSection>		</StructureSection>
	[[Category: HIV-1 retropepsin]]		[[Category: HIV-1 retropepsin]]
		+	[[Category: Large Structures]]
	[[Category: King, N M]]		[[Category: King, N M]]
	[[Category: Nalivaika, E A]]		[[Category: Nalivaika, E A]]

OCA at 15:41, 12 October 2017

OCA — Thu, 12 Oct 2017 15:41:04 GMT

←Older revision		Revision as of 15:41, 12 October 2017
Line 1:		Line 1:
		+
	==CRYSTAL STRUCTURE OF AP2V SUBSTRATE VARIANT OF NC-P1 DECAMER PEPTIDE IN COMPLEX WITH V82A/D25N HIV-1 PROTEASE MUTANT==		==CRYSTAL STRUCTURE OF AP2V SUBSTRATE VARIANT OF NC-P1 DECAMER PEPTIDE IN COMPLEX WITH V82A/D25N HIV-1 PROTEASE MUTANT==
	<StructureSection load='1tsq' size='340' side='right' caption='[[1tsq]], [[Resolution\|resolution]] 2.00Å' scene=''>		<StructureSection load='1tsq' size='340' side='right' caption='[[1tsq]], [[Resolution\|resolution]] 2.00Å' scene=''>
Line 5:		Line 6:
	</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene></td></tr>		</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene></td></tr>
	<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/HIV-1_retropepsin HIV-1 retropepsin], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.23.16 3.4.23.16] </span></td></tr>		<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/HIV-1_retropepsin HIV-1 retropepsin], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.23.16 3.4.23.16] </span></td></tr>
-	<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1tsq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1tsq OCA], [http://pdbe.org/1tsq PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1tsq RCSB], [http://www.ebi.ac.uk/pdbsum/1tsq PDBsum]</span></td></tr>	+	<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1tsq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1tsq OCA], [http://pdbe.org/1tsq PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1tsq RCSB], [http://www.ebi.ac.uk/pdbsum/1tsq PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1tsq ProSAT]</span></td></tr>
	</table>		</table>
	== Function ==		== Function ==
Line 17:		Line 18:
	<text>to colour the structure by Evolutionary Conservation</text>		<text>to colour the structure by Evolutionary Conservation</text>
	</jmolCheckbox>		</jmolCheckbox>
-	</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary\|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/~~chain_selection~~.php?pdb_ID=~~2ata~~ ConSurf].	+	</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary\|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1tsq ConSurf].
	<div style="clear:both"></div>		<div style="clear:both"></div>
	<div style="background-color:#fffaf0;">		<div style="background-color:#fffaf0;">
Line 28:		Line 29:
	</div>		</div>
	<div class="pdbe-citations 1tsq" style="background-color:#fffaf0;"></div>		<div class="pdbe-citations 1tsq" style="background-color:#fffaf0;"></div>
		+
		+	==See Also==
		+	*[[Immunodeficiency virus protease\|Immunodeficiency virus protease]]
	== References ==		== References ==
	<references/>		<references/>

OCA at 23:06, 11 September 2015

OCA — Fri, 11 Sep 2015 23:06:12 GMT

←Older revision		Revision as of 23:06, 11 September 2015
Line 5:		Line 5:
	</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene></td></tr>		</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene></td></tr>
	<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/HIV-1_retropepsin HIV-1 retropepsin], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.23.16 3.4.23.16] </span></td></tr>		<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/HIV-1_retropepsin HIV-1 retropepsin], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.23.16 3.4.23.16] </span></td></tr>
-	<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1tsq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1tsq OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1tsq RCSB], [http://www.ebi.ac.uk/pdbsum/1tsq PDBsum]</span></td></tr>	+	<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1tsq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1tsq OCA], [http://pdbe.org/1tsq PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1tsq RCSB], [http://www.ebi.ac.uk/pdbsum/1tsq PDBsum]</span></td></tr>
	</table>		</table>
	== Function ==		== Function ==
Line 27:		Line 27:
	From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>		From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>
	</div>		</div>
		+	<div class="pdbe-citations 1tsq" style="background-color:#fffaf0;"></div>
	== References ==		== References ==
	<references/>		<references/>

OCA at 20:38, 25 December 2014

OCA — Thu, 25 Dec 2014 20:38:23 GMT

←Older revision		Revision as of 20:38, 25 December 2014
Line 3:		Line 3:
	== Structural highlights ==		== Structural highlights ==
	<table><tr><td colspan='2'>[[1tsq]] is a 3 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TSQ OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1TSQ FirstGlance]. <br>		<table><tr><td colspan='2'>[[1tsq]] is a 3 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TSQ OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1TSQ FirstGlance]. <br>
-	</td></tr><tr><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene><br>	+	</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene></td></tr>
-	<tr><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/HIV-1_retropepsin HIV-1 retropepsin], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.23.16 3.4.23.16] </span></td></tr>	+	<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/HIV-1_retropepsin HIV-1 retropepsin], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.23.16 3.4.23.16] </span></td></tr>
-	<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1tsq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1tsq OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1tsq RCSB], [http://www.ebi.ac.uk/pdbsum/1tsq PDBsum]</span></td></tr>	+	<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1tsq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1tsq OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1tsq RCSB], [http://www.ebi.ac.uk/pdbsum/1tsq PDBsum]</span></td></tr>
-	<table>	+	</table>
		+	== Function ==
		+	[[http://www.uniprot.org/uniprot/POL_HV1A2 POL_HV1A2]] Gag-Pol polyprotein and Gag polyprotein may regulate their own translation, by the binding genomic RNA in the 5'-UTR. At low concentration, Gag-Pol and Gag would promote translation, whereas at high concentration, the polyproteins encapsidate genomic RNA and then shutt off translation (By similarity). Matrix protein p17 has two main functions: in infected cell, it targets Gag and Gag-pol polyproteins to the plasma membrane via a multipartite membrane-binding signal, that includes its myristoylated N-terminus. The second function is to play a role in nuclear localization of the viral genome at the very start of cell infection. Matrix protein is the part of the pre-integration complex. It binds in the cytoplasm the human BAF protein which prevent autointegration of the viral genome, and might be included in virions at the ration of zero to 3 BAF dimer per virion. The myristoylation signal and the NLS thus exert conflicting influences its subcellular localization. The key regulation of these motifs might be phosphorylation of a portion of MA molecules on the C-terminal tyrosine at the time of virus maturation, by virion-associated cellular tyrosine kinase. Implicated in the release from host cell mediated by Vpu (By similarity). Capsid protein p24 forms the conical core that encapsulates the genomic RNA-nucleocapsid complex in the virion. Most core are conical, with only 7% tubular. The core is constituted by capsid protein hexamer subunits. The core is disassembled soon after virion entry. Interaction with human PPIA/CYPA protects the virus from restriction by human TRIM5-alpha and from an unknown antiviral activity in human cells. This capsid restriction by TRIM5 is one of the factors which restricts HIV-1 to the human species (By similarity). Nucleocapsid protein p7 encapsulates and protects viral dimeric unspliced (genomic) RNA. Binds these RNAs through its zinc fingers. Facilitates rearangement of nucleic acid secondary structure during retrotranscription of genomic RNA. This capability is referred to as nucleic acid chaperone activity (By similarity). The aspartyl protease mediates proteolytic cleavages of Gag and Gag-Pol polyproteins during or shortly after the release of the virion from the plasma membrane. Cleavages take place as an ordered, step-wise cascade to yield mature proteins. This process is called maturation. Displays maximal activity during the budding process just prior to particle release from the cell. Also cleaves Nef and Vif, probably concomitantly with viral structural proteins on maturation of virus particles (By similarity). Reverse transcriptase/ribonuclease H (RT) is a multifunctional enzyme that converts the viral RNA genome into dsDNA in the cytoplasm, shortly after virus entry into the cell. This enzyme displays a DNA polymerase activity that can copy either DNA or RNA templates, and a ribonuclease H (RNase H) activity that cleaves the RNA strand of RNA-DNA heteroduplexes in a partially processive 3' to 5' endonucleasic mode. Conversion of viral genomic RNA into dsDNA requires many steps. A tRNA(3)-Lys binds to the primer-binding site (PBS) situated at the 5'-end of the viral RNA. RT uses the 3' end of the tRNA primer to perform a short round of RNA-dependent minus-strand DNA synthesis. The reading proceeds through the U5 region and ends after the repeated (R) region which is present at both ends of viral RNA. The portion of the RNA-DNA heteroduplex is digested by the RNase H, resulting in a ssDNA product attached to the tRNA primer. This ssDNA/tRNA hybridizes with the identical R region situated at the 3' end of viral RNA. This template exchange, known as minus-strand DNA strong stop transfer, can be either intra- or intermolecular. RT uses the 3' end of this newly synthesized short ssDNA to perform the RNA-dependent minus-strand DNA synthesis of the whole template. RNase H digests the RNA template except for two polypurine tracts (PPTs) situated at the 5'-end and near the center of the genome. It is not clear if both polymerase and RNase H activities are simultaneous. RNase H probably can proceed both in a polymerase-dependent (RNA cut into small fragments by the same RT performing DNA synthesis) and a polymerase-independent mode (cleavage of remaining RNA fragments by free RTs). Secondly, RT performs DNA-directed plus-strand DNA synthesis using the PPTs that have not been removed by RNase H as primers. PPTs and tRNA primers are then removed by RNase H. The 3' and 5' ssDNA PBS regions hybridize to form a circular dsDNA intermediate. Strand displacement synthesis by RT to the PBS and PPT ends produces a blunt ended, linear dsDNA copy of the viral genome that includes long terminal repeats (LTRs) at both ends (By similarity). Integrase catalyzes viral DNA integration into the host chromosome, by performing a series of DNA cutting and joining reactions. This enzyme activity takes place after virion entry into a cell and reverse transcription of the RNA genome in dsDNA. The first step in the integration process is 3' processing. This step requires a complex comprising the viral genome, matrix protein, Vpr and integrase. This complex is called the pre-integration complex (PIC). The integrase protein removes 2 nucleotides from each 3' end of the viral DNA, leaving recessed CA OH's at the 3' ends. In the second step, the PIC enters cell nucleus. This process is mediated through integrase and Vpr proteins, and allows the virus to infect a non dividing cell. This ability to enter the nucleus is specific of lentiviruses, other retroviruses cannot and rely on cell division to access cell chromosomes. In the third step, termed strand transfer, the integrase protein joins the previously processed 3' ends to the 5' ends of strands of target cellular DNA at the site of integration. The 5'-ends are produced by integrase-catalyzed staggered cuts, 5 bp apart. A Y-shaped, gapped, recombination intermediate results, with the 5'-ends of the viral DNA strands and the 3' ends of target DNA strands remaining unjoined, flanking a gap of 5 bp. The last step is viral DNA integration into host chromosome. This involves host DNA repair synthesis in which the 5 bp gaps between the unjoined strands are filled in and then ligated. Since this process occurs at both cuts flanking the HIV genome, a 5 bp duplication of host DNA is produced at the ends of HIV-1 integration. Alternatively, Integrase may catalyze the excision of viral DNA just after strand transfer, this is termed disintegration (By similarity). [[http://www.uniprot.org/uniprot/GAG_HV1H2 GAG_HV1H2]] Matrix protein p17 targets Gag and Gag-Pol polyproteins to the plasma membrane via a multipartite membrane binding signal, that includes its myristoylated N-terminus. Also mediates nuclear localization of the preintegration complex. Implicated in the release from host cell mediated by Vpu. Capsid protein p24 forms the conical core of the virus that encapsulates the genomic RNA-nucleocapsid complex. Nucleocapsid protein p7 encapsulates and protects viral dimeric unspliced (genomic) RNA. Binds these RNAs through its zinc fingers. p6-gag plays a role in budding of the assembled particle by interacting with the host class E VPS proteins TSG101 and PDCD6IP/AIP1 (By similarity).
	== Evolutionary Conservation ==		== Evolutionary Conservation ==
	[[Image:Consurf_key_small.gif\|200px\|right]]		[[Image:Consurf_key_small.gif\|200px\|right]]
Line 30:		Line 32:
	</StructureSection>		</StructureSection>
	[[Category: HIV-1 retropepsin]]		[[Category: HIV-1 retropepsin]]
-	[[Category: King, N M.]]	+	[[Category: King, N M]]
-	[[Category: Nalivaika, E A.]]	+	[[Category: Nalivaika, E A]]
-	[[Category: Prabu-Jeyabalan, M.]]	+	[[Category: Prabu-Jeyabalan, M]]
-	[[Category: Schiffer, C A.]]	+	[[Category: Schiffer, C A]]
	[[Category: Co-evolution]]		[[Category: Co-evolution]]
	[[Category: Hiv-1 protease]]		[[Category: Hiv-1 protease]]

OCA at 09:55, 3 October 2014

OCA — Fri, 03 Oct 2014 09:55:32 GMT

←Older revision		Revision as of 09:55, 3 October 2014
Line 1:		Line 1:
-	[[~~Image~~:1tsq.~~png\|left~~\|200px]]	+	==CRYSTAL STRUCTURE OF AP2V SUBSTRATE VARIANT OF NC-P1 DECAMER PEPTIDE IN COMPLEX WITH V82A/D25N HIV-1 PROTEASE MUTANT==
		+	<StructureSection load='1tsq' size='340' side='right' caption='[[1tsq]], [[Resolution\|resolution]] 2.00Å' scene=''>
		+	== Structural highlights ==
		+	<table><tr><td colspan='2'>[[1tsq]] is a 3 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TSQ OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1TSQ FirstGlance]. <br>
		+	</td></tr><tr><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene><br>
		+	<tr><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/HIV-1_retropepsin HIV-1 retropepsin], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.23.16 3.4.23.16] </span></td></tr>
		+	<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1tsq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1tsq OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1tsq RCSB], [http://www.ebi.ac.uk/pdbsum/1tsq PDBsum]</span></td></tr>
		+	<table>
		+	== Evolutionary Conservation ==
		+	[[Image:Consurf_key_small.gif\|200px\|right]]
		+	Check<jmol>
		+	<jmolCheckbox>
		+	<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ts/1tsq_consurf.spt"</scriptWhenChecked>
		+	<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
		+	<text>to colour the structure by Evolutionary Conservation</text>
		+	</jmolCheckbox>
		+	</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary\|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/chain_selection.php?pdb_ID=2ata ConSurf].
		+	<div style="clear:both"></div>
		+	<div style="background-color:#fffaf0;">
		+	== Publication Abstract from PubMed ==
		+	Maturation of human immunodeficiency virus (HIV) depends on the processing of Gag and Pol polyproteins by the viral protease, making this enzyme a prime target for anti-HIV therapy. Among the protease substrates, the nucleocapsid-p1 (NC-p1) sequence is the least homologous, and its cleavage is the rate-determining step in viral maturation. In the other substrates of HIV-1 protease, P1 is usually either a hydrophobic or an aromatic residue, and P2 is usually a branched residue. NC-p1, however, contains Asn at P1 and Ala at P2. In response to the V82A drug-resistant protease mutation, the P2 alanine of NC-p1 mutates to valine (AP2V). To provide a structural rationale for HIV-1 protease binding to the NC-p1 cleavage site, we solved the crystal structures of inactive (D25N) WT and V82A HIV-1 proteases in complex with their respective WT and AP2V mutant NC-p1 substrates. Overall, the WT NC-p1 peptide binds HIV-1 protease less optimally than the AP2V mutant, as indicated by the presence of fewer hydrogen bonds and fewer van der Waals contacts. AlaP2 does not fill the P2 pocket completely; PheP1' makes van der Waals interactions with Val82 that are lost with the V82A protease mutation. This loss is compensated by the AP2V mutation, which reorients the peptide to a conformation more similar to that observed in other substrate-protease complexes. Thus, the mutant substrate not only binds the mutant protease more optimally but also reveals the interdependency between the P1' and P2 substrate sites. This structural interdependency results from coevolution of the substrate with the viral protease.

-	~~{{STRUCTURE_1tsq\| PDB=1tsq \| SCENE= }}~~	+	Structural basis for coevolution of a human immunodeficiency virus type 1 nucleocapsid-p1 cleavage site with a V82A drug-resistant mutation in viral protease.,Prabu-Jeyabalan M, Nalivaika EA, King NM, Schiffer CA J Virol. 2004 Nov;78(22):12446-54. PMID:15507631<ref>PMID:15507631</ref>

-	~~===CRYSTAL STRUCTURE OF AP2V SUBSTRATE VARIANT OF NC-P1 DECAMER PEPTIDE IN COMPLEX WITH V82A~~/~~D25N HIV-1 PROTEASE MUTANT===~~	+	From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>
-		+	</div>
-	~~{{ABSTRACT_PUBMED_15507631}}~~	+	== References ==
-		+	<references/>
-	~~==About this Structure==~~	+	__TOC__
-	~~[[1tsq]] is~~ a ~~3 chain structure~~. ~~Full crystallographic information is available from [http://oca~~.~~weizmann~~.~~ac.il~~/~~oca-bin/ocashort?id=1TSQ OCA].~~	+	</StructureSection>
-		+
-	==~~Reference~~==	+
-	<~~ref group="xtra">PMID:015507631<~~/~~ref~~><~~references group="xtra"~~/>	+
	[[Category: HIV-1 retropepsin]]		[[Category: HIV-1 retropepsin]]
	[[Category: King, N M.]]		[[Category: King, N M.]]

OCA: Protected "1tsq" [edit=sysop:move=sysop]

OCA — Sat, 05 Jan 2013 13:28:54 GMT

Protected "1tsq" [edit=sysop:move=sysop]

←Older revision

Revision as of 13:28, 5 January 2013

OCA at 13:28, 5 January 2013

OCA — Sat, 05 Jan 2013 13:28:52 GMT

←Older revision		Revision as of 13:28, 5 January 2013
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-	{{Seed}}
	[[Image:1tsq.png\|left\|200px]]		[[Image:1tsq.png\|left\|200px]]

-	<!--
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	{{STRUCTURE_1tsq\| PDB=1tsq \| SCENE= }}		{{STRUCTURE_1tsq\| PDB=1tsq \| SCENE= }}

	===CRYSTAL STRUCTURE OF AP2V SUBSTRATE VARIANT OF NC-P1 DECAMER PEPTIDE IN COMPLEX WITH V82A/D25N HIV-1 PROTEASE MUTANT===		===CRYSTAL STRUCTURE OF AP2V SUBSTRATE VARIANT OF NC-P1 DECAMER PEPTIDE IN COMPLEX WITH V82A/D25N HIV-1 PROTEASE MUTANT===

-
-	<!--
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	{{ABSTRACT_PUBMED_15507631}}		{{ABSTRACT_PUBMED_15507631}}

	==About this Structure==		==About this Structure==
-	~~1TSQ~~ is a 3 ~~chains~~ structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TSQ OCA].	+	[[1tsq]] is a 3 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TSQ OCA].

	==Reference==		==Reference==
-	<ref group="xtra">PMID:~~15507631~~</ref><references group="xtra"/>	+	<ref group="xtra">PMID:015507631</ref><references group="xtra"/>
	[[Category: HIV-1 retropepsin]]		[[Category: HIV-1 retropepsin]]
	[[Category: King, N M.]]		[[Category: King, N M.]]
Line 31:		Line 19:
	[[Category: Co-evolution]]		[[Category: Co-evolution]]
	[[Category: Hiv-1 protease]]		[[Category: Hiv-1 protease]]
		+	[[Category: Hydrolase-viral protein complex]]
	[[Category: Nucleocapdi]]		[[Category: Nucleocapdi]]
	[[Category: Substrate recognition]]		[[Category: Substrate recognition]]
-
-	''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Wed Feb 18 06:31:27 2009''

OCA at 04:31, 18 February 2009

OCA — Wed, 18 Feb 2009 04:31:29 GMT

←Older revision		Revision as of 04:31, 18 February 2009
Line 20:		Line 20:

	==About this Structure==		==About this Structure==
-	1TSQ is a ~~[[Protein complex]]~~ structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TSQ OCA].	+	1TSQ is a 3 chains structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TSQ OCA].

	==Reference==		==Reference==
-	Structural basis for coevolution of a human immunodeficiency virus type 1 nucleocapsid-p1 cleavage site with a V82A drug-resistant mutation in viral protease., Prabu-Jeyabalan M, Nalivaika EA, King NM, Schiffer CA, J Virol. 2004 Nov;78(22):12446-54. PMID:~~[http:~~//~~www.ncbi.nlm.nih.gov/pubmed/15507631 15507631]~~	+	<ref group="xtra">PMID:15507631</ref><references group="xtra"/>
	[[Category: HIV-1 retropepsin]]		[[Category: HIV-1 retropepsin]]
-	[[Category: Protein complex]]
	[[Category: King, N M.]]		[[Category: King, N M.]]
	[[Category: Nalivaika, E A.]]		[[Category: Nalivaika, E A.]]
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	[[Category: Substrate recognition]]		[[Category: Substrate recognition]]

-	''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on ~~Tue Jul 29 13~~:14:~~29 2008~~''	+	''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Wed Feb 18 06:31:27 2009''