View source for 8efy


==Structure of double homo-hexameric AAA+ ATPase RuvB motors==
<StructureSection load='8efy' size='340' side='right'caption='[[8efy]], [[Resolution|resolution]] 3.16&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8efy]] is a 16 chain structure with sequence from [https://en.wikipedia.org/wiki/Thermus_thermophilus_HB8 Thermus thermophilus HB8]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8EFY OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8EFY FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 3.16&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ADP:ADENOSINE-5-DIPHOSPHATE'>ADP</scene>, <scene name='pdbligand=AGS:PHOSPHOTHIOPHOSPHORIC+ACID-ADENYLATE+ESTER'>AGS</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</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=8efy FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8efy OCA], [https://pdbe.org/8efy PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8efy RCSB], [https://www.ebi.ac.uk/pdbsum/8efy PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8efy ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/RUVB_THET8 RUVB_THET8] The RuvA-RuvB complex in the presence of ATP renatures cruciform structure in supercoiled DNA with palindromic sequence, indicating that it may promote strand exchange reactions in homologous recombination. RuvAB is a helicase that mediates the Holliday junction migration by localized denaturation and reannealing. RuvB is a Mg(2+)-dependent, DNA-dependent ATPase with an equal preference for supercoiled and linear duplex DNA. It can promote Holliday junction migration alone.<ref>PMID:10485292</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The Holliday junction (HJ) is a DNA intermediate of homologous recombination, involved in many fundamental physiological processes. RuvB, an ATPase motor protein, drives branch migration of the Holliday junction with a mechanism that had yet to be elucidated. Here we report two cryo-EM structures of RuvB, providing a comprehensive understanding of HJ branch migration. RuvB assembles into a spiral staircase, ring-like hexamer, encircling dsDNA. Four protomers of RuvB contact the DNA backbone with a translocation step size of 2 nucleotides. The variation of nucleotide-binding states in RuvB supports a sequential model for ATP hydrolysis and nucleotide recycling, which occur at separate, singular positions. RuvB's asymmetric assembly also explains the 6:4 stoichiometry between the RuvB/RuvA complex, which coordinates HJ migration in bacteria. Taken together, we provide a mechanistic understanding of HJ branch migration facilitated by RuvB, which may be universally shared by prokaryotic and eukaryotic organisms.

Molecular mechanisms of Holliday junction branch migration catalyzed by an asymmetric RuvB hexamer.,Rish AD, Shen Z, Chen Z, Zhang N, Zheng Q, Fu TM Nat Commun. 2023 Jun 15;14(1):3549. doi: 10.1038/s41467-023-39250-6. PMID:37322069<ref>PMID:37322069</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 8efy" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Thermus thermophilus HB8]]
[[Category: Fu TM]]
[[Category: Rish AD]]
[[Category: Shen ZF]]