title: Reconstruction of bacterial transcription-coupled repair at single-molecule resolution.
abstract: Escherichia coli Mfd translocase enables transcription-coupled repair by displacing RNA polymerase (RNAP) stalled on a DNA lesion and then coordinating assembly of the UvrAB(C) components at the damage site. Recent studies have shown that after binding to and dislodging stalled RNAP, Mfd remains on the DNA in the form of a stable, slowly translocating complex with evicted RNAP attached. Here we find, using a series of single-molecule assays, that recruitment of UvrA and UvrAB to Mfd-RNAP arrests the translocating complex and causes its dissolution. Correlative single-molecule nanomanipulation and fluorescence measurements show that dissolution of the complex leads to loss of both RNAP and Mfd. Subsequent DNA incision by UvrC is faster than when only UvrAB(C) are available, in part because UvrAB binds 20-200 times more strongly to Mfd–RNAP than to DNA damage. These observations provide a quantitative framework for comparing complementary DNA repair pathways in vivo.
authors.forename: Jun
authors.initials: J
authors.lastname: Fan
authors.forename: Mathieu
authors.initials: M
authors.lastname: Leroux-Coyau
authors.forename: Nigel J
authors.initials: NJ
authors.lastname: Savery
authors.forename: Terence R
authors.initials: TR
authors.lastname: Strick
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism; D004249:DNA Damage; D004265:DNA Helicases / Q000378:metabolism; D004260:DNA Repair; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D004706:Endodeoxyribonucleases / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000378:metabolism; D008954:Models, Biological; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D014157:Transcription Factors; C058093:UvrB protein, E coli; C072103:transcription repair coupling factor protein, Bacteria; D012321:DNA-Directed RNA Polymerases; D004706:Endodeoxyribonucleases; C066567:UvrC protein, E coli; C068631:UvrA protein, E coli; D000251:Adenosine Triphosphatases; D004265:DNA Helicases