8GH8

RuvA Holliday junction DNA complex

Summary for 8GH8

• Entry DOI: 10.2210/pdb8gh8/pdb
• EMDB information: 40036
• Descriptor: Holliday junction branch migration complex subunit RuvA, DNA (34-MER) (3 entities in total)
• Functional Keywords: holliday junction, tetramer, ruva, dna binding protein, dna binding protein-dna complex, dna binding protein/dna
• Biological source: Thermus thermophilus HB8; More
• Total number of polymer chains: 8
• Total formula weight: 101555.61

Authors

Rish, A.D.,Fu, T. (deposition date: 2023-03-09, release date: 2023-05-10, Last modification date: 2024-11-20)

Primary citation

Rish, A.D.,Shen, Z.,Chen, Z.,Zhang, N.,Zheng, Q.,Fu, T.M.
Molecular mechanisms of Holliday junction branch migration catalyzed by an asymmetric RuvB hexamer.
Nat Commun, 14:3549-3549, 2023

PubMed Abstract: 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.

PubMed: 37322069
DOI: 10.1038/s41467-023-39250-6

Experimental method

ELECTRON MICROSCOPY (4.3 Å)