Replication fork collapse at a protein ‐DNA roadblock leads to fork reversal, promoted by the RecQ helicase

This study shows that replication fork regression, the combination of replication fork reversal (RFR) leading to formation of a Holliday Junction (HJ) along with exonuclease digestion, is the preferred pathway for dealing with a collapsed fork inEscherichia coli. Direct endo ‐nuclease activity at the replication fork was not observed. The protein that had the greatest effect on these fork processing events was the RecQ helicase, while RecG and RuvABC, which have previously been implicated in this process, were found to play a lesser role. Eukaryotic RecQ homologues, B LM and WRN, have also been implicated in processing events following replication fork collapse and may reflect a conserved mechanism. Finally, the SOS response was not induced by the protein‐DNA roadblock under these conditions, so did not affect fork processing.This article is protected by copyright. All rights reserved.
Source: Molecular Microbiology - Category: Microbiology Authors: Tags: Research Article Source Type: research