UvsW protein regulates bacteriophage T4 origin-dependent replication by unwinding R-loops.

Published

Journal Article

The UvsW protein of bacteriophage T4 is involved in many aspects of phage DNA metabolism, including repair, recombination, and recombination-dependent replication. UvsW has also been implicated in the repression of origin-dependent replication at late times of infection, when UvsW is normally synthesized. Two well-characterized T4 origins, ori(uvsY) and ori(34), are believed to initiate replication through an R-loop mechanism. Here we provide both in vivo and in vitro evidence that UvsW is an RNA-DNA helicase that catalyzes the dissociation of RNA from origin R-loops. Two-dimensional gel analyses show that the replicative intermediates formed at ori(uvsY) persist longer in a uvsW mutant infection than in a wild-type infection. In addition, the inappropriate early expression of UvsW protein results in the loss of these replicative intermediates. Using a synthetic origin R-loop, we also demonstrate that purified UvsW functions as a helicase that efficiently dissociates RNA from R-loops. These and previous results from a number of studies provide strong evidence that UvsW is a molecular switch that allows T4 replication to progress from a mode that initiates from R-loops at origins to a mode that initiates from D-loops formed by recombination proteins.

Full Text

Duke Authors

Cited Authors

  • Dudas, KC; Kreuzer, KN

Published Date

  • April 2001

Published In

Volume / Issue

  • 21 / 8

Start / End Page

  • 2706 - 2715

PubMed ID

  • 11283250

Pubmed Central ID

  • 11283250

International Standard Serial Number (ISSN)

  • 0270-7306

Digital Object Identifier (DOI)

  • 10.1128/MCB.21.8.2706-2715.2001

Language

  • eng

Conference Location

  • United States