4ep3 - Revision history

OCA at 11:04, 1 March 2024

2024-03-01T11:04:38Z

←Older revision		Revision as of 11:04, 1 March 2024
Line 4:		Line 4:
	== Structural highlights ==		== Structural highlights ==
	<table><tr><td colspan='2'>[[4ep3]] is a 2 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/Human_immunodeficiency_virus_1 Human immunodeficiency virus 1]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4EP3 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4EP3 FirstGlance]. <br>		<table><tr><td colspan='2'>[[4ep3]] is a 2 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/Human_immunodeficiency_virus_1 Human immunodeficiency virus 1]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4EP3 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4EP3 FirstGlance]. <br>
-	</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BME:BETA-MERCAPTOETHANOL'>BME</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</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]] 1.81Å</td></tr>
		+	<tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BME:BETA-MERCAPTOETHANOL'>BME</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</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=4ep3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4ep3 OCA], [https://pdbe.org/4ep3 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4ep3 RCSB], [https://www.ebi.ac.uk/pdbsum/4ep3 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4ep3 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=4ep3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4ep3 OCA], [https://pdbe.org/4ep3 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4ep3 RCSB], [https://www.ebi.ac.uk/pdbsum/4ep3 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4ep3 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/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).
-	~~<div style="background-color:#fffaf0;">~~	+
-	~~== Publication Abstract from PubMed ==~~	+
-	HIV-1 protease recognizes and cleaves more than 12 different substrates leading to viral maturation. While these substrates share no conserved motif, they are specifically selected for and cleaved by protease during viral life cycle. Drug resistant mutations evolve within the protease that compromise inhibitor binding but allow the continued recognition of all these substrates. While the substrate envelope defines a general shape for substrate recognition, successfully predicting the determinants of substrate binding specificity would provide additional insights into the mechanism of altered molecular recognition in resistant proteases. We designed a variant of HIV protease with altered specificity using positive computational design methods and validated the design using x-ray crystallography and enzyme biochemistry. The engineered variant, Pr3 (A28S/D30F/G48R), was designed to preferentially bind to one out of three of HIV protease's natural substrates; RT-RH over p2-NC and CA-p2. In kinetic assays, RT-RH binding specificity for Pr3 increased three-fold compared to the wild-type (WT), which was further confirmed by isothermal titration calorimetry. Crystal structures of WT protease and the designed variant in complex with RT-RH, CA-p2 and p2-NC were determined. Structural analysis of the designed complexes revealed that one of the engineered substitutions (G48R) potentially stabilized heterogeneous flap conformations, thereby facilitating alternate modes of substrate binding. Our results demonstrate that while substrate specificity could be engineered in HIV protease, the structural pliability of protease restricted the propagation of interactions as predicted. These results offer new insights into the plasticity and structural determinants of substrate binding specificity of the HIV-1 protease.	+
-		+
-	Structural, kinetic, and thermodynamic studies of specificity designed HIV-1 protease.,Alvizo O, Mittal S, Mayo SL, Schiffer CA Protein Sci. 2012 May 1. doi: 10.1002/pro.2086. PMID:22549928<ref>PMID:22549928</ref>	+
-		+
-	~~From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>~~	+
-	~~</div>~~	+
-	~~<div class="pdbe-citations 4ep3" style="background-color:#fffaf0;"></div>~~	+

	==See Also==		==See Also==
	*[[Immunodeficiency virus protease 3D structures\|Immunodeficiency virus protease 3D structures]]		*[[Immunodeficiency virus protease 3D structures\|Immunodeficiency virus protease 3D structures]]
-	== References ==
-	<references/>
	__TOC__		__TOC__
	</StructureSection>		</StructureSection>

OCA at 07:21, 28 September 2022

2022-09-28T07:21:23Z

←Older revision		Revision as of 07:21, 28 September 2022
Line 1:		Line 1:

	==Crystal Structure of inactive single chain wild-type HIV-1 Protease in Complex with the substrate CA-p2==		==Crystal Structure of inactive single chain wild-type HIV-1 Protease in Complex with the substrate CA-p2==
-	<StructureSection load='4ep3' size='340' side='right' caption='[[4ep3]], [[Resolution\|resolution]] 1.81Å' scene=''>	+	<StructureSection load='4ep3' size='340' side='right'caption='[[4ep3]], [[Resolution\|resolution]] 1.81Å' scene=''>
	== Structural highlights ==		== Structural highlights ==
-	<table><tr><td colspan='2'>[[4ep3]] is a 2 chain structure with sequence from [~~http~~://en.wikipedia.org/wiki/~~Hiv~~-~~1 Hiv~~-1]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4EP3 OCA]. For a <b>guided tour on the structure components</b> use [~~http~~://~~oca~~.~~weizmann.ac.il/oca-docs~~/fgij/fg.htm?mol=4EP3 FirstGlance]. <br>	+	<table><tr><td colspan='2'>[[4ep3]] is a 2 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/Human_immunodeficiency_virus_1 Human immunodeficiency virus 1]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4EP3 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4EP3 FirstGlance]. <br>
-	</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=BME:BETA-MERCAPTOETHANOL'>BME</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene~~></td></tr>~~	+	</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BME:BETA-MERCAPTOETHANOL'>BME</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene></td></tr>
-	~~<tr id='related'><td class="sblockLbl"><b>[[Related_structure\|Related:]]</b></td><td class="sblockDat">[[4ep2\|4ep2]], [[4epj\|4epj]], [[4eq0\|4eq0]], [[4eqj\|4eqj]]</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=4ep3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4ep3 OCA], [https://pdbe.org/4ep3 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4ep3 RCSB], [https://www.ebi.ac.uk/pdbsum/4ep3 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4ep3 ProSAT]</span></td></tr>
-	~~<tr id='gene'><td class="sblockLbl"><b>[[Gene\|Gene:]]</b></td><td class="sblockDat">gag-pol ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=11685 HIV-1])</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=4ep3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4ep3 OCA], [~~http~~://pdbe.org/4ep3 PDBe], [~~http~~://www.rcsb.org/pdb/explore.do?structureId=4ep3 RCSB], [~~http~~://www.ebi.ac.uk/pdbsum/4ep3 PDBsum], [~~http~~://prosat.h-its.org/prosat/prosatexe?pdbcode=4ep3 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/Q9YP46_9HIV1 Q9YP46_9HIV1]] Capsid protein p24 forms the conical core of the virus that encapsulates the genomic RNA-nucleocapsid complex (By similarity).[SAAS:SAAS012344_004_008806] Nucleocapsid protein p7 encapsulates and protects viral dimeric unspliced (genomic) RNA. Binds these RNAs through its zinc fingers (By similarity).[SAAS:SAAS012344_004_011858]	+	[[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).
	<div style="background-color:#fffaf0;">		<div style="background-color:#fffaf0;">
	== Publication Abstract from PubMed ==		== Publication Abstract from PubMed ==
Line 21:		Line 18:
	</div>		</div>
	<div class="pdbe-citations 4ep3" style="background-color:#fffaf0;"></div>		<div class="pdbe-citations 4ep3" style="background-color:#fffaf0;"></div>
		+
		+	==See Also==
		+	*[[Immunodeficiency virus protease 3D structures\|Immunodeficiency virus protease 3D structures]]
	== References ==		== References ==
	<references/>		<references/>
	__TOC__		__TOC__
	</StructureSection>		</StructureSection>
-	[[Category: HIV-1 ~~retropepsin]]~~	+	[[Category: HIV-1 M:B_ARV2/SF2]]
-	~~[[Category~~: ~~Hiv-1~~]]	+	[[Category: Human immunodeficiency virus 1]]
-	[[Category: ~~Mittal, S]]~~	+	[[Category: Large Structures]]
-	~~[[Category: Schiffer, C A]]~~	+	[[Category: Mittal S]]
-	~~[[Category: Aid]]~~	+	[[Category: Schiffer CA]]
-	~~[[Category: Aspartyl protease]]~~	+
-	~~[[Category: Drug design]]~~	+
-	~~[[Category: Hiv-~~1 ~~protease~~]]	+
-	[[Category: ~~Hydrolase~~]]	+
-	[[Category: ~~Hydrolase-hydrolase substrate complex~~]]	+
-	[[Category: ~~Protease inhibitor]]~~	+
-	~~[[Category: Specificity design~~]]	+

OCA at 09:51, 5 August 2016

2016-08-05T09:51:15Z

←Older revision		Revision as of 09:51, 5 August 2016
Line 1:		Line 1:
		+
	==Crystal Structure of inactive single chain wild-type HIV-1 Protease in Complex with the substrate CA-p2==		==Crystal Structure of inactive single chain wild-type HIV-1 Protease in Complex with the substrate CA-p2==
	<StructureSection load='4ep3' size='340' side='right' caption='[[4ep3]], [[Resolution\|resolution]] 1.81Å' scene=''>		<StructureSection load='4ep3' size='340' side='right' caption='[[4ep3]], [[Resolution\|resolution]] 1.81Å' scene=''>
	== Structural highlights ==		== Structural highlights ==
-	<table><tr><td colspan='2'>[[4ep3]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Hiv-~~1_m:b_arv2/sf2~~ Hiv-1 ~~m:b_arv2/sf2~~]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4EP3 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4EP3 FirstGlance]. <br>	+	<table><tr><td colspan='2'>[[4ep3]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Hiv-1 Hiv-1]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4EP3 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4EP3 FirstGlance]. <br>
	</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=BME:BETA-MERCAPTOETHANOL'>BME</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene></td></tr>		</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=BME:BETA-MERCAPTOETHANOL'>BME</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene></td></tr>
	<tr id='related'><td class="sblockLbl"><b>[[Related_structure\|Related:]]</b></td><td class="sblockDat">[[4ep2\|4ep2]], [[4epj\|4epj]], [[4eq0\|4eq0]], [[4eqj\|4eqj]]</td></tr>		<tr id='related'><td class="sblockLbl"><b>[[Related_structure\|Related:]]</b></td><td class="sblockDat">[[4ep2\|4ep2]], [[4epj\|4epj]], [[4eq0\|4eq0]], [[4eqj\|4eqj]]</td></tr>
-	<tr id='gene'><td class="sblockLbl"><b>[[Gene\|Gene:]]</b></td><td class="sblockDat">gag-pol ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=11685 HIV-1 ~~M:B_ARV2/SF2~~])</td></tr>	+	<tr id='gene'><td class="sblockLbl"><b>[[Gene\|Gene:]]</b></td><td class="sblockDat">gag-pol ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=11685 HIV-1])</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=4ep3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4ep3 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4ep3 RCSB], [http://www.ebi.ac.uk/pdbsum/4ep3 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=4ep3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4ep3 OCA], [http://pdbe.org/4ep3 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4ep3 RCSB], [http://www.ebi.ac.uk/pdbsum/4ep3 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4ep3 ProSAT]</span></td></tr>
	</table>		</table>
	== Function ==		== Function ==
Line 19:		Line 20:
	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 4ep3" style="background-color:#fffaf0;"></div>
	== References ==		== References ==
	<references/>		<references/>
Line 24:		Line 26:
	</StructureSection>		</StructureSection>
	[[Category: HIV-1 retropepsin]]		[[Category: HIV-1 retropepsin]]
-	[[Category: Hiv-1 ~~m:b_arv2/sf2~~]]	+	[[Category: Hiv-1]]
	[[Category: Mittal, S]]		[[Category: Mittal, S]]
	[[Category: Schiffer, C A]]		[[Category: Schiffer, C A]]

OCA at 01:20, 25 December 2014

2014-12-25T01:20:36Z

←Older revision		Revision as of 01:20, 25 December 2014
Line 9:		Line 9:
	<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=4ep3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4ep3 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4ep3 RCSB], [http://www.ebi.ac.uk/pdbsum/4ep3 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=4ep3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4ep3 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4ep3 RCSB], [http://www.ebi.ac.uk/pdbsum/4ep3 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/Q9YP46_9HIV1 Q9YP46_9HIV1]] Capsid protein p24 forms the conical core of the virus that encapsulates the genomic RNA-nucleocapsid complex (By similarity).[SAAS:SAAS012344_004_008806] Nucleocapsid protein p7 encapsulates and protects viral dimeric unspliced (genomic) RNA. Binds these RNAs through its zinc fingers (By similarity).[SAAS:SAAS012344_004_011858]
	<div style="background-color:#fffaf0;">		<div style="background-color:#fffaf0;">
	== Publication Abstract from PubMed ==		== Publication Abstract from PubMed ==

OCA at 17:09, 9 December 2014

2014-12-09T17:09:52Z

←Older revision		Revision as of 17:09, 9 December 2014
Line 1:		Line 1:
-	[[~~Image:~~4ep3.~~png~~\|~~left~~\|~~200px~~]]	+	==Crystal Structure of inactive single chain wild-type HIV-1 Protease in Complex with the substrate CA-p2==
		+	<StructureSection load='4ep3' size='340' side='right' caption='[[4ep3]], [[Resolution\|resolution]] 1.81Å' scene=''>
		+	== Structural highlights ==
		+	<table><tr><td colspan='2'>[[4ep3]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Hiv-1_m:b_arv2/sf2 Hiv-1 m:b_arv2/sf2]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4EP3 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4EP3 FirstGlance]. <br>
		+	</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=BME:BETA-MERCAPTOETHANOL'>BME</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene></td></tr>
		+	<tr id='related'><td class="sblockLbl"><b>[[Related_structure\|Related:]]</b></td><td class="sblockDat">[[4ep2\|4ep2]], [[4epj\|4epj]], [[4eq0\|4eq0]], [[4eqj\|4eqj]]</td></tr>
		+	<tr id='gene'><td class="sblockLbl"><b>[[Gene\|Gene:]]</b></td><td class="sblockDat">gag-pol ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=11685 HIV-1 M:B_ARV2/SF2])</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=4ep3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4ep3 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4ep3 RCSB], [http://www.ebi.ac.uk/pdbsum/4ep3 PDBsum]</span></td></tr>
		+	</table>
		+	<div style="background-color:#fffaf0;">
		+	== Publication Abstract from PubMed ==
		+	HIV-1 protease recognizes and cleaves more than 12 different substrates leading to viral maturation. While these substrates share no conserved motif, they are specifically selected for and cleaved by protease during viral life cycle. Drug resistant mutations evolve within the protease that compromise inhibitor binding but allow the continued recognition of all these substrates. While the substrate envelope defines a general shape for substrate recognition, successfully predicting the determinants of substrate binding specificity would provide additional insights into the mechanism of altered molecular recognition in resistant proteases. We designed a variant of HIV protease with altered specificity using positive computational design methods and validated the design using x-ray crystallography and enzyme biochemistry. The engineered variant, Pr3 (A28S/D30F/G48R), was designed to preferentially bind to one out of three of HIV protease's natural substrates; RT-RH over p2-NC and CA-p2. In kinetic assays, RT-RH binding specificity for Pr3 increased three-fold compared to the wild-type (WT), which was further confirmed by isothermal titration calorimetry. Crystal structures of WT protease and the designed variant in complex with RT-RH, CA-p2 and p2-NC were determined. Structural analysis of the designed complexes revealed that one of the engineered substitutions (G48R) potentially stabilized heterogeneous flap conformations, thereby facilitating alternate modes of substrate binding. Our results demonstrate that while substrate specificity could be engineered in HIV protease, the structural pliability of protease restricted the propagation of interactions as predicted. These results offer new insights into the plasticity and structural determinants of substrate binding specificity of the HIV-1 protease.

-	~~{{STRUCTURE_4ep3\| PDB=4ep3 \| SCENE= }}~~	+	Structural, kinetic, and thermodynamic studies of specificity designed HIV-1 protease.,Alvizo O, Mittal S, Mayo SL, Schiffer CA Protein Sci. 2012 May 1. doi: 10.1002/pro.2086. PMID:22549928<ref>PMID:22549928</ref>

-	~~===Crystal Structure~~ of ~~inactive single chain wild-type HIV-1 Protease in Complex with~~ the ~~substrate CA-p2===~~	+	From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>
-		+	</div>
-	~~{{ABSTRACT_PUBMED_22549928}}~~	+	== References ==
-		+	<references/>
-	~~==About this Structure==~~	+	__TOC__
-	~~[[4ep3]] is a 2 chain structure with sequence from [http://en~~.~~wikipedia~~.~~org/wiki/Hiv-1_m:b_arv2/sf2 Hiv-1 m:b_arv2/sf2]~~. ~~Full crystallographic information is available from [http:~~/~~/oca.weizmann.ac.il/oca-bin/ocashort?id=4EP3 OCA].~~	+	</StructureSection>
-		+
-	==~~Reference~~==	+
-	<~~ref group="xtra">PMID:022549928<~~/~~ref~~><~~references group="xtra"~~/>	+
	[[Category: HIV-1 retropepsin]]		[[Category: HIV-1 retropepsin]]
	[[Category: Hiv-1 m:b_arv2/sf2]]		[[Category: Hiv-1 m:b_arv2/sf2]]
-	[[Category: Mittal, S.]]	+	[[Category: Mittal, S]]
-	[[Category: Schiffer, C A.]]	+	[[Category: Schiffer, C A]]
	[[Category: Aid]]		[[Category: Aid]]
	[[Category: Aspartyl protease]]		[[Category: Aspartyl protease]]

OCA at 08:29, 9 January 2013

2013-01-09T08:29:57Z

←Older revision		Revision as of 08:29, 9 January 2013
Line 1:		Line 1:
-	[[Image:4ep3.~~jpg~~\|left\|200px]]	+	[[Image:4ep3.png\|left\|200px]]

-	<!--
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	{{STRUCTURE_4ep3\| PDB=4ep3 \| SCENE= }}		{{STRUCTURE_4ep3\| PDB=4ep3 \| SCENE= }}

	===Crystal Structure of inactive single chain wild-type HIV-1 Protease in Complex with the substrate CA-p2===		===Crystal Structure of inactive single chain wild-type HIV-1 Protease in Complex with the substrate CA-p2===

-
-	<!--
-	The line below this paragraph, {{ABSTRACT_PUBMED_22549928}}, adds the Publication Abstract to the page
-	(as it appears on PubMed at http://www.pubmed.gov), where 22549928 is the PubMed ID number.
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	{{ABSTRACT_PUBMED_22549928}}		{{ABSTRACT_PUBMED_22549928}}

OCA at 07:37, 6 June 2012

2012-06-06T07:37:08Z

←Older revision		Revision as of 07:37, 6 June 2012
Line 1:		Line 1:
-	~~'''Unreleased structure'''~~	+	[[Image:4ep3.jpg\|left\|200px]]

-	The ~~entry 4ep3~~ is ~~ON HOLD~~	+	<!--
		+	The line below this paragraph, containing "STRUCTURE_4ep3", creates the "Structure Box" on the page.
		+	You may change the PDB parameter (which sets the PDB file loaded into the applet)
		+	or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
		+	or leave the SCENE parameter empty for the default display.
		+	-->
		+	{{STRUCTURE_4ep3\| PDB=4ep3 \| SCENE= }}

-	~~Authors: Schiffer, C.A., Mittal, S.~~	+	===Crystal Structure of inactive single chain wild-type HIV-1 Protease in Complex with the substrate CA-p2===

-	~~Description~~: ~~Crystal~~ Structure ~~of inactive single~~ chain ~~wild~~-~~type~~ HIV-1 ~~Protease in Complex with the substrate CA~~-p2	+
		+	<!--
		+	The line below this paragraph, {{ABSTRACT_PUBMED_22549928}}, adds the Publication Abstract to the page
		+	(as it appears on PubMed at http://www.pubmed.gov), where 22549928 is the PubMed ID number.
		+	-->
		+	{{ABSTRACT_PUBMED_22549928}}
		+
		+	==About this Structure==
		+	[[4ep3]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Hiv-1_m:b_arv2/sf2 Hiv-1 m:b_arv2/sf2]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4EP3 OCA].
		+
		+	==Reference==
		+	<ref group="xtra">PMID:022549928</ref><references group="xtra"/>
		+	[[Category: HIV-1 retropepsin]]
		+	[[Category: Hiv-1 m:b_arv2/sf2]]
		+	[[Category: Mittal, S.]]
		+	[[Category: Schiffer, C A.]]
		+	[[Category: Aid]]
		+	[[Category: Aspartyl protease]]
		+	[[Category: Drug design]]
		+	[[Category: Hiv-1 protease]]
		+	[[Category: Hydrolase]]
		+	[[Category: Hydrolase-hydrolase substrate complex]]
		+	[[Category: Protease inhibitor]]
		+	[[Category: Specificity design]]

OCA: Protected "4ep3" [edit=sysop:move=sysop]

2012-04-25T08:56:02Z

Protected "4ep3" [edit=sysop:move=sysop]

←Older revision

Revision as of 08:56, 25 April 2012

OCA: New page: '''Unreleased structure''' The entry 4ep3 is ON HOLD Authors: Schiffer, C.A., Mittal, S. Description: Crystal Structure of inactive single chain wild-type HIV-1 Protease in Complex wit...

2012-04-25T08:56:01Z

New page: '''Unreleased structure''' The entry 4ep3 is ON HOLD Authors: Schiffer, C.A., Mittal, S. Description: Crystal Structure of inactive single chain wild-type HIV-1 Protease in Complex wit...

New page

'''Unreleased structure'''

The entry 4ep3 is ON HOLD

Authors: Schiffer, C.A., Mittal, S.

Description: Crystal Structure of inactive single chain wild-type HIV-1 Protease in Complex with the substrate CA-p2