View source for 4zc0


==Structure of a dodecameric bacterial helicase==
<StructureSection load='4zc0' size='340' side='right'caption='[[4zc0]], [[Resolution|resolution]] 6.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4zc0]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Helicobacter_pylori Helicobacter pylori]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4ZC0 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4ZC0 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]] 6.7&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=TBR:HEXATANTALUM+DODECABROMIDE'>TBR</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=4zc0 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4zc0 OCA], [https://pdbe.org/4zc0 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4zc0 RCSB], [https://www.ebi.ac.uk/pdbsum/4zc0 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4zc0 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/DNAB_HELPY DNAB_HELPY] Participates in initiation and elongation during chromosome replication; it exhibits DNA-dependent ATPase activity and contains distinct active sites for ATP binding, DNA binding, and interaction with DnaC protein, primase, and other prepriming proteins (By similarity).
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Replicative helicases are essential ATPases that unwind DNA to initiate chromosomal replication. While bacterial replicative DnaB helicases are hexameric, Helicobacter pylori DnaB (HpDnaB) was found to form double hexamers, similar to some archaeal and eukaryotic replicative helicases. Here we present a structural and functional analysis of HpDnaB protein during primosome formation. The crystal structure of the HpDnaB at 6.7 A resolution reveals a dodecameric organization consisting of two hexamers assembled via their N-terminal rings in a stack-twisted mode. Using fluorescence anisotropy we show that HpDnaB dodecamer interacts with single-stranded DNA in the presence of ATP but has a low DNA unwinding activity. Multi-angle light scattering and small angle X-ray scattering demonstrate that interaction with the DnaG primase helicase-binding domain dissociates the helicase dodecamer into single ringed primosomes. Functional assays on the proteins and associated complexes indicate that these single ringed primosomes are the most active form of the helicase for ATP hydrolysis, DNA binding and unwinding. These findings shed light onto an activation mechanism of HpDnaB by the primase that might be relevant in other bacteria and possibly other organisms exploiting dodecameric helicases for DNA replication.

Structure and primase-mediated activation of a bacterial dodecameric replicative helicase.,Bazin A, Cherrier MV, Gutsche I, Timmins J, Terradot L Nucleic Acids Res. 2015 Sep 30;43(17):8564-76. doi: 10.1093/nar/gkv792. Epub 2015, Aug 11. PMID:26264665<ref>PMID:26264665</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4zc0" style="background-color:#fffaf0;"></div>

==See Also==
*[[Helicase 3D structures|Helicase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Helicobacter pylori]]
[[Category: Large Structures]]
[[Category: Bazin A]]
[[Category: Cherrier MV]]
[[Category: Gutsche I]]
[[Category: Terradot L]]
[[Category: Timmins J]]