Complementary strand relocation may play vital roles in RecA-based homology recognition.

ABSTRACT: RecA-family proteins mediate homologous recombination and recombinational DNA repair through homology search and strand exchange. Initially, the protein forms a filament with the incoming single-stranded DNA (ssDNA) bound in site I. The RecA-ssDNA filament then binds double-stranded DNA (dsDNA) in site II. Non-homologous dsDNA rapidly unbinds, whereas homologous dsDNA undergoes strand exchange yielding heteroduplex dsDNA in site I and the leftover outgoing strand in site II. We show that applying force to the ends of the complementary strand significantly retards strand exchange, whereas applying the same force to the outgoing strand does not. We also show that crystallographically determined binding site locations require an intermediate structure in addition to the initial and final stru

SUBMITTER: Peacock-Villada A 

PROVIDER: S-EPMC3488227 | biostudies-literature | 2012 Nov

REPOSITORIES: biostudies-literature