title: The Escherichia coli replisome is inherently DNA damage tolerant.
abstract: The Escherichia coli DNA replication machinery must frequently overcome template lesions under normal growth conditions. Yet, the outcome of a collision between the replisome and a leading-strand template lesion remains poorly understood. Here, we demonstrate that a single, site-specific, cyclobutane pyrimidine dimer leading-strand template lesion provides only a transient block to fork progression in vitro. The replisome remains stably associated with the fork after collision with the lesion. Leading-strand synthesis is then reinitiated downstream of the damage in a reaction that is dependent on the primase, DnaG, but independent of any of the known replication-restart proteins. These observations reveal that the replisome can tolerate leading-strand template lesions without dissociating by synthesizing the leading strand discontinuously.
authors: Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA.
authors: Joseph T P
authors: JT
authors: Yeeles
authors: Kenneth J
authors: KJ
authors: Marians
mesh_terms: D004249:DNA Damage; D004258:DNA Polymerase III / Q000378:metabolism; D019915:DNA Primase; D004261:DNA Replication; D004269:DNA, Bacterial / Q000096:biosynthesis*; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D004706:Endodeoxyribonucleases / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000378:metabolism*; D005090:Exodeoxyribonucleases / Q000378:metabolism; D009097:Multienzyme Complexes / Q000378:metabolism*; D010957:Plasmids; D011740:Pyrimidine Dimers; D018741:Replication Origin; D013698:Templates, Genetic; D000099272:Replisomes
chemical_list: D004258:DNA Polymerase III; D019915:DNA Primase; D004269:DNA, Bacterial; D004259:DNA-Directed DNA Polymerase; D004706:Endodeoxyribonucleases; D029968:Escherichia coli Proteins; D005090:Exodeoxyribonucleases; D009097:Multienzyme Complexes; D011740:Pyrimidine Dimers; D000099272:Replisomes; C121791:dnaG protein, E coli