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==Structure of bacteriophage T7 E343Q mutant gp4 helicase-primase in complex with ssDNA, dTTP, AC dinucleotide and CTP (form I)== | |||
<StructureSection load='6n7n' size='340' side='right' caption='[[6n7n]], [[Resolution|resolution]] 3.50Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[6n7n]] is a 7 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6N7N OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6N7N FirstGlance]. <br> | |||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=TTP:THYMIDINE-5-TRIPHOSPHATE'>TTP</scene></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=6n7n FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6n7n OCA], [http://pdbe.org/6n7n PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6n7n RCSB], [http://www.ebi.ac.uk/pdbsum/6n7n PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6n7n ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[[http://www.uniprot.org/uniprot/PRIM_BPT7 PRIM_BPT7]] Synthesizes short RNA primers for DNA replication. Unwinds the DNA at the replication forks and generates single-stranded DNA for both leading and lagging strand synthesis. The primase synthesizes short RNA primers on the lagging strand that the polymerase elongates using dNTPs.<ref>PMID:9096333</ref> <ref>PMID:21606333</ref> <ref>PMID:22977246</ref> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Visualization in atomic detail of the replisome that performs concerted leading- and lagging-DNA strand synthesis at a replication fork has not been reported. Using bacteriophage T7 as a model system, we determined cryo-electron microscopy structures up to 3.2-angstroms resolution of helicase translocating along DNA and of helicase-polymerase-primase complexes engaging in synthesis of both DNA strands. Each domain of the spiral-shaped hexameric helicase translocates sequentially hand-over-hand along a single-stranded DNA coil, akin to the way AAA+ ATPases (adenosine triphosphatases) unfold peptides. Two lagging-strand polymerases are attached to the primase, ready for Okazaki fragment synthesis in tandem. A beta hairpin from the leading-strand polymerase separates two parental DNA strands into a T-shaped fork, thus enabling the closely coupled helicase to advance perpendicular to the downstream DNA duplex. These structures reveal the molecular organization and operating principles of a replisome. | |||
Structures and operating principles of the replisome.,Gao Y, Cui Y, Fox T, Lin S, Wang H, de Val N, Zhou ZH, Yang W Science. 2019 Feb 22;363(6429). pii: science.aav7003. doi:, 10.1126/science.aav7003. Epub 2019 Jan 24. PMID:30679383<ref>PMID:30679383</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
[[Category: | </div> | ||
<div class="pdbe-citations 6n7n" style="background-color:#fffaf0;"></div> | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Cui, Y]] | |||
[[Category: Gao, Y]] | [[Category: Gao, Y]] | ||
[[Category: | [[Category: Yang, W]] | ||
[[Category: Zhou, Z]] | [[Category: Zhou, Z]] | ||
[[Category: | [[Category: Atpase]] | ||
[[Category: Dna replication]] | |||
[[Category: Helicase]] | |||
[[Category: Hexamer]] | |||
[[Category: Hydrolase]] | |||
[[Category: Transferase-dna complex]] | |||
Revision as of 10:33, 6 March 2019
Structure of bacteriophage T7 E343Q mutant gp4 helicase-primase in complex with ssDNA, dTTP, AC dinucleotide and CTP (form I)Structure of bacteriophage T7 E343Q mutant gp4 helicase-primase in complex with ssDNA, dTTP, AC dinucleotide and CTP (form I)
Structural highlights
Function[PRIM_BPT7] Synthesizes short RNA primers for DNA replication. Unwinds the DNA at the replication forks and generates single-stranded DNA for both leading and lagging strand synthesis. The primase synthesizes short RNA primers on the lagging strand that the polymerase elongates using dNTPs.[1] [2] [3] Publication Abstract from PubMedVisualization in atomic detail of the replisome that performs concerted leading- and lagging-DNA strand synthesis at a replication fork has not been reported. Using bacteriophage T7 as a model system, we determined cryo-electron microscopy structures up to 3.2-angstroms resolution of helicase translocating along DNA and of helicase-polymerase-primase complexes engaging in synthesis of both DNA strands. Each domain of the spiral-shaped hexameric helicase translocates sequentially hand-over-hand along a single-stranded DNA coil, akin to the way AAA+ ATPases (adenosine triphosphatases) unfold peptides. Two lagging-strand polymerases are attached to the primase, ready for Okazaki fragment synthesis in tandem. A beta hairpin from the leading-strand polymerase separates two parental DNA strands into a T-shaped fork, thus enabling the closely coupled helicase to advance perpendicular to the downstream DNA duplex. These structures reveal the molecular organization and operating principles of a replisome. Structures and operating principles of the replisome.,Gao Y, Cui Y, Fox T, Lin S, Wang H, de Val N, Zhou ZH, Yang W Science. 2019 Feb 22;363(6429). pii: science.aav7003. doi:, 10.1126/science.aav7003. Epub 2019 Jan 24. PMID:30679383[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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