title: Transcription-coupled DNA repair in prokaryotes.
abstract: Transcription-coupled repair (TCR) is a subpathway of nucleotide excision repair (NER) that acts specifically on lesions in the transcribed strand of expressed genes. First reported in mammalian cells, TCR was then documented in Escherichia coli. In this organism, an RNA polymerase arrested at a lesion is displaced by the transcription repair coupling factor, Mfd. This protein recruits the NER lesion-recognition factor UvrA, and then dissociates from the DNA. UvrA binds UvrB, and the assembled UvrAB* complex initiates repair. In mutants lacking active Mfd, TCR is absent. A gene transcribed by the bacteriophage T7 RNA polymerase in E. coli also requires Mfd for TCR. The CSB protein (missing or defective in cells of patients with Cockayne syndrome, complementation group B) is essential for TCR in humans. CSB and its homologs in higher eukaryotes are likely functional equivalents of Mfd.
authors: Department of Biology, Stanford University, Stanford, California, USA.
authors: Ann
authors: A
authors: Ganesan
authors: Graciela
authors: G
authors: Spivak
authors: Philip C
authors: PC
authors: Hanawalt
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism; D004249:DNA Damage / Q000235:genetics; D004260:DNA Repair / Q000235:genetics*; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D011387:Prokaryotic Cells / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D012321:DNA-Directed RNA Polymerases