The poor homology stringency in the heteroduplex allows strand exchange to incorporate desirable mismatches without sacrificing recognition in vivo.

ABSTRACT: RecA family proteins are responsible for homology search and strand exchange. In bacteria, homology search begins after RecA binds an initiating single-stranded DNA (ssDNA) in the primary DNA-binding site, forming the presynaptic filament. Once the filament is formed, it interrogates double-stranded DNA (dsDNA). During the interrogation, bases in the dsDNA attempt to form Watson-Crick bonds with the corresponding bases in the initiating strand. Mismatch dependent instability in the base pairing in the heteroduplex strand exchange product could provide stringent recognition; however, we present experimental and theoretical results suggesting that the heteroduplex stability is insensitive to mismatches. We also present data suggesting that an initial homology test of 8 contiguous bases rejec

SUBMITTER: Danilowicz C 

PROVIDER: S-EPMC4513875 | biostudies-literature | 2015 Jul

REPOSITORIES: biostudies-literature