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1q57

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(New page: 200px<br /><applet load="1q57" size="450" color="white" frame="true" align="right" spinBox="true" caption="1q57, resolution 3.45&Aring;" /> '''The Crystal Structur...)
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[[Image:1q57.jpg|left|200px]]<br /><applet load="1q57" size="450" color="white" frame="true" align="right" spinBox="true"
 
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caption="1q57, resolution 3.45&Aring;" />
 
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'''The Crystal Structure of the Bifunctional Primase-Helicase of Bacteriophage T7'''<br />
 
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==Overview==
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==The Crystal Structure of the Bifunctional Primase-Helicase of Bacteriophage T7==
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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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<StructureSection load='1q57' size='340' side='right'caption='[[1q57]], [[Resolution|resolution]] 3.45&Aring;' scene=''>
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== Structural highlights ==
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<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>
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</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 3.45&#8491;</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=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>
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</table>
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== Function ==
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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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== Evolutionary Conservation ==
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[[Image:Consurf_key_small.gif|200px|right]]
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Check<jmol>
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<jmolCheckbox>
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<scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/q5/1q57_consurf.spt"</scriptWhenChecked>
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<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
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<text>to colour the structure by Evolutionary Conservation</text>
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</jmolCheckbox>
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</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].
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<div style="clear:both"></div>
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==About this Structure==
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==See Also==
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1Q57 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacteriophage_t7 Bacteriophage t7]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1Q57 OCA].
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*[[RNA polymerase 3D structures|RNA polymerase 3D structures]]
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== References ==
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==Reference==
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<references/>
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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:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=14636571 14636571]
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__TOC__
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[[Category: Bacteriophage t7]]
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</StructureSection>
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[[Category: Single protein]]
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[[Category: Escherichia phage T7]]
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[[Category: Cheng, Y.]]
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[[Category: Large Structures]]
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[[Category: Ellenberger, T.]]
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[[Category: Cheng Y]]
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[[Category: Li, Y.]]
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[[Category: Ellenberger T]]
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[[Category: Sawaya, M.R.]]
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[[Category: Li Y]]
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[[Category: Toth, E.A.]]
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[[Category: Sawaya MR]]
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[[Category: dna replication]]
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[[Category: Toth EA]]
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[[Category: dntpase]]
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[[Category: helicase]]
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[[Category: primase]]
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''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Wed Nov 21 00:23:35 2007''
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Current revision

The Crystal Structure of the Bifunctional Primase-Helicase of Bacteriophage T7

PDB ID 1q57

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