Bacteriophage T4 UvsW protein is a helicase involved in recombination, repair and the regulation of DNA replication origins.

Published

Journal Article

Bacteriophage T4 UvsW protein is involved in phage recombination, repair and the regulation of replication origins. Here, we provide evidence that UvsW functions as a helicase. First, expression of UvsW allows growth of an (otherwise inviable) Escherichia coli recG rnhA double mutant, consistent with UvsW being a functional analog of the RecG helicase. Second, UvsW contains helicase sequence motifs, and a substitution (K141R) in the Walker 'A' motif prevents growth of the E.coli recG rnhA double mutant. Third, UvsW, but not UvsW-K141R, inhibits replication from a T4 origin at which persistent RNA-DNA hybrids form and presumably trigger replication initiation. Fourth, mutations that inactivate UvsW and endonuclease VII (which cleaves DNA branches) synergistically block repair of double-strand breaks. These in vivo results are consistent with a model in which UvsW is a DNA helicase that catalyzes branch migration and dissociation of RNA-DNA hybrids. In support of this model, a partially purified GST/UvsW fusion protein, but not a GST/UvsW-K141R fusion, displays ssDNA-dependent ATPase activity and is able to unwind a branched DNA substrate.

Full Text

Duke Authors

Cited Authors

  • Carles-Kinch, K; George, JW; Kreuzer, KN

Published Date

  • July 1, 1997

Published In

Volume / Issue

  • 16 / 13

Start / End Page

  • 4142 - 4151

PubMed ID

  • 9233823

Pubmed Central ID

  • 9233823

International Standard Serial Number (ISSN)

  • 0261-4189

Digital Object Identifier (DOI)

  • 10.1093/emboj/16.13.4142

Language

  • eng

Conference Location

  • England