Article
The T4 Phage UvsW Protein Contains Both DNA Unwinding and Strand Annealing Activities
Journal of Biological Chemistry
(2007)
Abstract
UvsW protein belongs to the SF2 helicase family and is one of
three helicases found in T4 phage. UvsW governs the transition
from origin-dependent to origin-independent replication
through the dissociation of R-loops located at the T4 origins of
replication. Additionally, in vivo evidence indicates that UvsW
plays a role in recombination-dependent replication and/or
DNA repair. Here, the biochemical properties of UvsW helicase
are described. UvsW is a 3 to 5 helicase that unwinds a wide
variety of substrates, including those resembling stalled replication
forks and recombination intermediates. UvsW also contains
a potent single-strand DNA annealing activity that is
enhanced byATPhydrolysis but does not require it. The annealing
activity is inhibited by the non-hydrolysable ATP analog
(adenosine 5-O-(thiotriphosphate)), T4 single-stranded DNAbinding
protein (gp32), or a small 8.8-kDa polypeptide
(UvsW.1). Fluorescence resonance energy transfer experiments
indicate thatUvsWand UvsW.1 form a complex, suggesting that
the UvsW helicase may exist as a heterodimer in vivo. Fusion of
UvsW and UvsW.1 results in a 68-kDa protein having nearly
identical properties as the UvsW-UvsW.1 complex, indicating
that the binding locus of UvsW.1 is close to the C terminus of
UvsW. The biochemical properties of UvsW are similar to the
RecQ protein family and suggest that the annealing activity of
these helicases may also be modulated by protein-protein interactions.
The dual activities of UvsW are well suited for the DNA
repair pathways described for leading strand lesion bypass and
synthesis-dependent strand annealing.
Keywords
- Annealing activity,
- Lesion bypass,
- Biochemistry,
- Energy transfer,
- Hydrolysis,
- protein UvsW,
- RecQ helicase,
- single stranded DNA,
- Bacteriophage T4
Disciplines
Publication Date
January, 2007
DOI
10.1074/jbc.M608153200
Publisher Statement
This article is from Journal of Biological Chemistry 282 (2007): 407, doi:10.1074/jbc.M608153200 . Posted with permission.
Citation Information
Scott W. Nelson and Stephen J. Benkovic. "The T4 Phage UvsW Protein Contains Both DNA Unwinding and Strand Annealing Activities" Journal of Biological Chemistry Vol. 282 Iss. 1 (2007) p. 407 - 416 Available at: http://works.bepress.com/scott-nelson/4/