Promotion of Rad51-dependent D-loop formation by yeast recombination factor Rdh54/Tid1

Galina Petukhova; Patrick Sung; Hannah Klein

doi:10.1101/gad.826100

Promotion of Rad51-dependent D-loop formation by yeast recombination factor Rdh54/Tid1

¹Department of Molecular Medicine and Institute of Biotechnology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78245-3207 USA; ²Department of Biochemistry and Kaplan Cancer Center, New York University, School of Medicine, New York, New York 10016 USA

Abstract

The first DNA joint formed in homologous recombination processes is a D-loop. Saccharomyces cerevisiae RDH54/TID1-encoded product, a Swi2/Snf2-like factor involved in recombination, is shown here to promote D-loop formation with Rad51 recombinase. Physical interaction between Rdh54 and Rad51 is functionally important because Rdh54 does not enhance the recombinase activity of the Escherichia coliRecA protein. Robust dsDNA-activated ATPase activity in Rdh54 generates unconstrained negative and positive supercoils in DNA. Efficient D-loop formation occurs with even topologically relaxed DNA, suggesting that via specific protein–protein interactions, the negative supercoils produced by Rdh54 are used by Rad51 for making DNA joints.

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Footnotes

↵3 Present address: National Institutes of Health, NIDDK, Building 10, Room 9D17, 9000 Rockville Pike, Bethesda, MD 20892 USA.
↵4 Corresponding authors.
E-MAIL sung{at}uthscsa.edu; FAX (210) 567-7277.
E-MAIL hannah.klein{at}med.nyu.edu; FAX (212) 263-8166.
Article and publication are at www.genesdev.org/cgi/doi/10.1101/gad.826100.
- Received June 9, 2000.
- Accepted July 11, 2000.
Cold Spring Harbor Laboratory Press