Direct restart of a replication fork stalled by a head-on RNA polymerase.
In vivo studies suggest that replication forks are arrested by encounters with head-on transcription complexes. Yet, the fate of the replisome and RNA polymerase (RNAP) after a head-on collision is unknown. We found that the Escherichia coli replisome stalls upon collision with a head-on transcription complex, but instead of collapsing, the replication fork remains highly stable and eventually resumes elongation after displacing the RNAP from DNA. We also found that the transcription-repair coupling factor Mfd promotes direct restart of the fork after the collision by facilitating displacement of the RNAP. These findings demonstrate the intrinsic stability of the replication apparatus and a previously unknown role for the transcription-coupled repair pathway in promoting replication past a RNAP block.
Pomerantz
Richard T
RT
The Rockefeller University, Howard Hughes Medical Institute, 1230 York Avenue, New York, NY 10021, USA.
O'Donnell
Mike
M
D001426:Bacterial Proteins / Q000378:metabolism; D004260:DNA Repair; D004261:DNA Replication; D004269:DNA, Bacterial / Q000378:metabolism*; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000378:metabolism; D013698:Templates, Genetic; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D014157:Transcription Factors; C072103:transcription repair coupling factor protein, Bacteria; D012321:DNA-Directed RNA Polymerases; D004259:DNA-Directed DNA Polymerase