Single-molecule imaging reveals molecular coupling between transcription and DNA repair machinery in live cells.

ABSTRACT: The Escherichia coli transcription-repair coupling factor Mfd displaces stalled RNA polymerase and delivers the stall site to the nucleotide excision repair factors UvrAB for damage detection. Whether this handoff from RNA polymerase to UvrA occurs via the Mfd-UvrA₂-UvrB complex or alternate reaction intermediates in cells remains unclear. Here, we visualise Mfd in actively growing cells and determine the catalytic requirements for faithful recruitment of nucleotide excision repair proteins. We find that ATP hydrolysis by UvrA governs formation and disassembly of the Mfd-UvrA₂ complex. Further, Mfd-UvrA₂-UvrB complexes formed by UvrB mutants deficient in DNA loading and damage recognition are impaired in successful handoff. Our single-molecule dissection of

SUBMITTER: Ho HN 

PROVIDER: S-EPMC7083905 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature