Single bacterial resolvases first exploit, then constrain intrinsic dynamics of the Holliday junction to direct recombination.

ABSTRACT: Homologous recombination forms and resolves an entangled DNA Holliday Junction (HJ) crucial for achieving genetic reshuffling and genome repair. To maintain genomic integrity, specialized resolvase enzymes cleave the entangled DNA into two discrete DNA molecules. However, it is unclear how two similar stacking isomers are distinguished, and how a cognate sequence is found and recognized to achieve accurate recombination. We here use single-molecule fluorescence observation and cluster analysis to examine how prototypic bacterial resolvase RuvC singles out two of the four HJ strands and achieves sequence-specific cleavage. We find that RuvC first exploits, then constrains the dynamics of intrinsic HJ isomer exchange at a sampled branch position to direct cleavage toward the catalytically co

SUBMITTER: Ray S 

PROVIDER: S-EPMC7969024 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature