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1q57
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==The Crystal Structure of the Bifunctional Primase-Helicase of Bacteriophage T7== | ==The Crystal Structure of the Bifunctional Primase-Helicase of Bacteriophage T7== | ||
| - | <StructureSection load='1q57' size='340' side='right' caption='[[1q57]], [[Resolution|resolution]] 3.45Å' scene=''> | + | <StructureSection load='1q57' size='340' side='right'caption='[[1q57]], [[Resolution|resolution]] 3.45Å' scene=''> |
== Structural highlights == | == Structural highlights == | ||
| - | <table><tr><td colspan='2'>[[1q57]] is a 7 chain structure with sequence from [ | + | <table><tr><td colspan='2'>[[1q57]] is a 7 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_phage_T7 Escherichia phage T7]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1Q57 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1Q57 FirstGlance]. <br> |
| - | </td></tr><tr id=' | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 3.45Å</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=1q57 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1q57 OCA], [https://pdbe.org/1q57 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1q57 RCSB], [https://www.ebi.ac.uk/pdbsum/1q57 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1q57 ProSAT]</span></td></tr> | |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[ | + | |
</table> | </table> | ||
== Function == | == Function == | ||
| - | [ | + | [https://www.uniprot.org/uniprot/HELIC_BPT7 HELIC_BPT7] ATP-dependent DNA helicase and primase essential for viral DNA replication and recombination (PubMed:21606333, PubMed:22977246, PubMed:32009150). The helicase moves 5' -> 3' on the lagging strand template, unwinding the DNA duplex ahead of the leading strand polymerase at the replication fork and generating ssDNA for both leading and lagging strand synthesis (PubMed:21606333, PubMed:22977246, PubMed:32009150). ATP or dTTP hydrolysis propels each helicase domain to translocate 2 nt per step sequentially along DNA (PubMed:30679383, PubMed:17604719). Mediates strand transfer when a joint molecule is available and participates in recombinational DNA repair through its role in strand exchange (PubMed:9096333, PubMed:8617248). Primase activity synthesizes short RNA primers at the sequence 5'-GTC-3' on the lagging strand that the polymerase elongates using dNTPs and providing the primase is still present (PubMed:6454135, PubMed:9139692).[HAMAP-Rule:MF_04154]<ref>PMID:17604719</ref> <ref>PMID:21606333</ref> <ref>PMID:22977246</ref> <ref>PMID:30679383</ref> <ref>PMID:32009150</ref> <ref>PMID:6454135</ref> <ref>PMID:8617248</ref> <ref>PMID:9096333</ref> <ref>PMID:9139692</ref> |
== Evolutionary Conservation == | == Evolutionary Conservation == | ||
[[Image:Consurf_key_small.gif|200px|right]] | [[Image:Consurf_key_small.gif|200px|right]] | ||
Check<jmol> | Check<jmol> | ||
<jmolCheckbox> | <jmolCheckbox> | ||
| - | <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/q5/1q57_consurf.spt"</scriptWhenChecked> | + | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/q5/1q57_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> | ||
</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/ | + | </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=1q57 ConSurf]. |
<div style="clear:both"></div> | <div style="clear:both"></div> | ||
| - | <div style="background-color:#fffaf0;"> | ||
| - | == Publication Abstract from PubMed == | ||
| - | Within minutes after infecting Escherichia coli, bacteriophage T7 synthesizes many copies of its genomic DNA. The lynchpin of the T7 replication system is a bifunctional primase-helicase that unwinds duplex DNA at the replication fork while initiating the synthesis of Okazaki fragments on the lagging strand. We have determined a 3.45 A crystal structure of the T7 primase-helicase that shows an articulated arrangement of the primase and helicase sites. The crystallized primase-helicase is a heptamer with a crown-like shape, reflecting an intimate packing of helicase domains into a ring that is topped with loosely arrayed primase domains. This heptameric isoform can accommodate double-stranded DNA in its central channel, which nicely explains its recently described DNA remodeling activity. The double-jointed structure of the primase-helicase permits a free range of motion for the primase and helicase domains that suggests how the continuous unwinding of DNA at the replication fork can be periodically coupled to Okazaki fragment synthesis. | ||
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| - | The crystal structure of the bifunctional primase-helicase of bacteriophage T7.,Toth EA, Li Y, Sawaya MR, Cheng Y, Ellenberger T Mol Cell. 2003 Nov;12(5):1113-23. PMID:14636571<ref>PMID:14636571</ref> | ||
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| - | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
| - | </div> | ||
==See Also== | ==See Also== | ||
| - | *[[RNA polymerase|RNA polymerase]] | + | *[[RNA polymerase 3D structures|RNA polymerase 3D structures]] |
== References == | == References == | ||
<references/> | <references/> | ||
__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||
| - | [[Category: | + | [[Category: Escherichia phage T7]] |
| - | [[Category: Cheng | + | [[Category: Large Structures]] |
| - | [[Category: Ellenberger | + | [[Category: Cheng Y]] |
| - | [[Category: Li | + | [[Category: Ellenberger T]] |
| - | [[Category: Sawaya | + | [[Category: Li Y]] |
| - | [[Category: Toth | + | [[Category: Sawaya MR]] |
| - | + | [[Category: Toth EA]] | |
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Current revision
The Crystal Structure of the Bifunctional Primase-Helicase of Bacteriophage T7
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