View source for 3pjr


==HELICASE SUBSTRATE COMPLEX==
<StructureSection load='3pjr' size='340' side='right'caption='[[3pjr]], [[Resolution|resolution]] 3.30&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3pjr]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Geobacillus_stearothermophilus Geobacillus stearothermophilus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3PJR OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3PJR FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 3.3&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ATP:ADENOSINE-5-TRIPHOSPHATE'>ATP</scene></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=3pjr FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3pjr OCA], [https://pdbe.org/3pjr PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3pjr RCSB], [https://www.ebi.ac.uk/pdbsum/3pjr PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3pjr ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/PCRA_GEOSE PCRA_GEOSE] DNA helicase. Has a broad nucleotide specificity, even being able to hydrolyze ethenonucleotides, and is able to couple the hydrolysis to unwinding of DNA substrates. It is a 3'-5' helicase but at high protein concentrations it can also displace a substrate with a 5' tail. Preferred substrate being one with both single and double-stranded regions of DNA.
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/pj/3pjr_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </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/main_output.php?pdb_ID=3pjr ConSurf].
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== Publication Abstract from PubMed ==
We have determined two different structures of PcrA DNA helicase complexed with the same single strand tailed DNA duplex, providing snapshots of different steps on the catalytic pathway. One of the structures is of a complex with a nonhydrolyzable analog of ATP and is thus a "substrate" complex. The other structure contains a bound sulphate ion that sits in a position equivalent to that occupied by the phosphate ion produced after ATP hydrolysis, thereby mimicking a "product" complex. In both complexes, the protein is monomeric. Large and distinct conformational changes occur on binding DNA and the nucleotide cofactor. Taken together, these structures provide evidence against an "active rolling" model for helicase action but are instead consistent with an "inchworm" mechanism.

Crystal structures of complexes of PcrA DNA helicase with a DNA substrate indicate an inchworm mechanism.,Velankar SS, Soultanas P, Dillingham MS, Subramanya HS, Wigley DB Cell. 1999 Apr 2;97(1):75-84. PMID:10199404<ref>PMID:10199404</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 3pjr" style="background-color:#fffaf0;"></div>

==See Also==
*[[Helicase|Helicase]]
*[[Helicase 3D structures|Helicase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Geobacillus stearothermophilus]]
[[Category: Large Structures]]
[[Category: Dillingham MS]]
[[Category: Soultanas P]]
[[Category: Subramanya HS]]
[[Category: Velankar SS]]
[[Category: Wigley DB]]