This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
1q57
From Proteopedia
(Difference between revisions)
| (One intermediate revision not shown.) | |||
| Line 3: | Line 3: | ||
<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]] | ||
| Line 20: | Line 19: | ||
</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]. | </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. | ||
| - | |||
| - | 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> | ||
| - | |||
| - | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
| - | </div> | ||
| - | <div class="pdbe-citations 1q57" style="background-color:#fffaf0;"></div> | ||
==See Also== | ==See Also== | ||
| Line 36: | Line 26: | ||
__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||
| - | [[Category: | + | [[Category: Escherichia phage T7]] |
[[Category: Large Structures]] | [[Category: Large Structures]] | ||
| - | [[Category: Cheng | + | [[Category: Cheng Y]] |
| - | [[Category: Ellenberger | + | [[Category: Ellenberger T]] |
| - | [[Category: Li | + | [[Category: Li Y]] |
| - | [[Category: Sawaya | + | [[Category: Sawaya MR]] |
| - | [[Category: Toth | + | [[Category: Toth EA]] |
| - | + | ||
| - | + | ||
| - | + | ||
| - | + | ||
| - | + | ||
Current revision
The Crystal Structure of the Bifunctional Primase-Helicase of Bacteriophage T7
| |||||||||||

