title: A proposal: Source of single strand DNA that elicits the SOS response.
abstract: Chromosome replication is performed by numerous proteins that function together as a "replisome". The replisome machinery duplicates both strands of the parental DNA simultaneously. Upon DNA damage to the cell, replisome action produces single-strand DNA to which RecA binds, enabling its activity in cleaving the LexA repressor and thus inducing the SOS response. How single-strand DNA is produced by a replisome acting on damaged DNA is not clear. For many years it has been assumed the single-strand DNA is generated by the replicative helicase, which continues unwinding DNA even after DNA polymerase stalls at a template lesion. Recent studies indicate another source of the single-strand DNA, resulting from an inherently dynamic replisome that may hop over template lesions on both leading and lagging strands, thereby leaving single-strand gaps in the wake of the replication fork. These single-strand gaps are proposed to be the origin of the single-strand DNA that triggers the SOS response after DNA damage.
authors.affiliation: Manhattan College 4513 Manhattan College Pkwy, Riverdale, NY 10471, USA. chiara.indiani@manhattan.edu
authors.forename: Chiara
authors.initials: C
authors.lastname: Indiani
authors.forename: Mike
authors.initials: M
authors.lastname: O'Donnell
mesh_terms: D004249:DNA Damage; D004265:DNA Helicases / Q000378:metabolism; D004258:DNA Polymerase III / Q000378:metabolism; D004261:DNA Replication; D004277:DNA, Single-Stranded / Q000096:biosynthesis*; D053488:DnaB Helicases / Q000378:metabolism; D008954:Models, Biological; D013014:SOS Response, Genetics / Q000502:physiology*
chemical_list: D004277:DNA, Single-Stranded; D004258:DNA Polymerase III; C506730:dnaB protein, E coli; D004265:DNA Helicases; D053488:DnaB Helicases