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6n7i

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==Structure of bacteriophage T7 E343Q mutant gp4 helicase-primase in complex with ssDNA, dTTP, AC dinucleotide and CTP (gp4(5)-DNA)==
==Structure of bacteriophage T7 E343Q mutant gp4 helicase-primase in complex with ssDNA, dTTP, AC dinucleotide and CTP (gp4(5)-DNA)==
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<StructureSection load='6n7i' size='340' side='right'caption='[[6n7i]], [[Resolution|resolution]] 3.20&Aring;' scene=''>
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<SX load='6n7i' size='340' side='right' viewer='molstar' caption='[[6n7i]], [[Resolution|resolution]] 3.20&Aring;' scene=''>
== Structural highlights ==
== Structural highlights ==
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<table><tr><td colspan='2'>[[6n7i]] is a 7 chain structure with sequence from [http://en.wikipedia.org/wiki/Bpt7 Bpt7]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6N7I OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6N7I FirstGlance]. <br>
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<table><tr><td colspan='2'>[[6n7i]] 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=6N7I OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6N7I FirstGlance]. <br>
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</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>
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</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 3.2&#8491;</td></tr>
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<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=6n7i FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6n7i OCA], [http://pdbe.org/6n7i PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6n7i RCSB], [http://www.ebi.ac.uk/pdbsum/6n7i PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6n7i ProSAT]</span></td></tr>
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<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=TTP:THYMIDINE-5-TRIPHOSPHATE'>TTP</scene></td></tr>
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<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=6n7i FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6n7i OCA], [https://pdbe.org/6n7i PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6n7i RCSB], [https://www.ebi.ac.uk/pdbsum/6n7i PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6n7i ProSAT]</span></td></tr>
</table>
</table>
== Function ==
== Function ==
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[[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>
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[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>
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<div style="background-color:#fffaf0;">
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== Publication Abstract from PubMed ==
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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.
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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>
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==See Also==
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*[[RNA polymerase 3D structures|RNA polymerase 3D structures]]
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From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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</div>
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<div class="pdbe-citations 6n7i" style="background-color:#fffaf0;"></div>
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== References ==
== References ==
<references/>
<references/>
__TOC__
__TOC__
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</StructureSection>
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</SX>
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[[Category: Bpt7]]
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[[Category: Escherichia phage T7]]
[[Category: Large Structures]]
[[Category: Large Structures]]
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[[Category: Cui, Y]]
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[[Category: Cui Y]]
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[[Category: Gao, Y]]
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[[Category: Gao Y]]
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[[Category: Yang, W]]
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[[Category: Yang W]]
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[[Category: Zhou, Z]]
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[[Category: Zhou Z]]
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[[Category: Atpase]]
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[[Category: Dna replication]]
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[[Category: Helicase]]
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[[Category: Hexamer]]
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[[Category: Hydrolase]]
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[[Category: Transferase-dna complex]]
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Current revision

Structure of bacteriophage T7 E343Q mutant gp4 helicase-primase in complex with ssDNA, dTTP, AC dinucleotide and CTP (gp4(5)-DNA)

6n7i, resolution 3.20Å

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