title: Rep provides a second motor at the replisome to promote duplication of protein-bound DNA.
abstract: Nucleoprotein complexes present challenges to genome stability by acting as potent blocks to replication. One attractive model of how such conflicts are resolved is direct targeting of blocked forks by helicases with the ability to displace the blocking protein-DNA complex. We show that Rep and UvrD each promote movement of E. coli replisomes blocked by nucleoprotein complexes in vitro, that such an activity is required to clear protein blocks (primarily transcription complexes) in vivo, and that a polarity of translocation opposite that of the replicative helicase is critical for this activity. However, these two helicases are not equivalent. Rep but not UvrD interacts physically and functionally with the replicative helicase. In contrast, UvrD likely provides a general means of protein-DNA complex turnover during replication, repair, and recombination. Rep and UvrD therefore provide two contrasting solutions as to how organisms may promote replication of protein-bound DNA.
authors: Institute of Medical Sciences, University of Aberdeen, Foresterhill, UK.
authors: Colin P
authors: CP
authors: Guy
authors: John
authors: J
authors: Atkinson
authors: Milind K
authors: MK
authors: Gupta
authors: Akeel A
authors: AA
authors: Mahdi
authors: Emma J
authors: EJ
authors: Gwynn
authors: Christian J
authors: CJ
authors: Rudolph
authors: Peter B
authors: PB
authors: Moon
authors: Ingeborg C
authors: IC
authors: van Knippenberg
authors: Chris J
authors: CJ
authors: Cadman
authors: Mark S
authors: MS
authors: Dillingham
authors: Robert G
authors: RG
authors: Lloyd
authors: Peter
authors: P
authors: McGlynn
mesh_terms: D003470:Culture Media; D004265:DNA Helicases / Q000378:metabolism*; D004261:DNA Replication; D004269:DNA, Bacterial / Q000378:metabolism*; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D053488:DnaB Helicases / Q000378:metabolism; D004926:Escherichia coli / Q000166:cytology / Q000201:enzymology / Q000254:growth & development; D029968:Escherichia coli Proteins / Q000378:metabolism*; D005816:Genetic Complementation Test; D020409:Molecular Motor Proteins / Q000378:metabolism*; D009097:Multienzyme Complexes / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D009698:Nucleoproteins / Q000378:metabolism; D011485:Protein Binding; D013489:Suppression, Genetic; D014158:Transcription, Genetic; D000099272:Replisomes
chemical_list: D003470:Culture Media; D004265:DNA Helicases; D004269:DNA, Bacterial; D004259:DNA-Directed DNA Polymerase; D053488:DnaB Helicases; D029968:Escherichia coli Proteins; D020409:Molecular Motor Proteins; D009097:Multienzyme Complexes; D009698:Nucleoproteins; D000099272:Replisomes; C506744:rep protein, E coli; C506746:UvrD protein, E coli; C506730:dnaB protein, E coli