RecBCD, SbcCD and ExoI process a substrate created by convergent replisomes to complete DNA replication.

ABSTRACT: The accurate completion of DNA replication on the chromosome requires RecBCD and structure specific SbcCD and ExoI nucleases. However, the substrates and mechanism by which this reaction occurs remains unknown. Here we show that these completion enzymes operate on plasmid substrates containing two replisomes, but are not required for plasmids containing one replisome. Completion on the two-replisome plasmids requires RecBCD, but does not require RecA and no broken intermediates accumulate in its absence, indicating that the completion reaction occurs normally in the absence of any double-strand breaks. Further, similar to the chromosome, we show that when the normal completion reaction is prevented, an aberrant RecA-mediated recombination process leads to amplifications that drive most of

SUBMITTER: Hamilton NA 

PROVIDER: S-EPMC6561825 | biostudies-literature | 2019 Jun

REPOSITORIES: biostudies-literature