4974 Nucleic Acids Research, 2008, Vol. 36, No. 15 19. Stelter,P. and Ulrich,H.D. (2003) Control of spontaneous and damage-induced mutagenesis by SUMO and ubiquitin conjugation. Nature, 425, 188–191. 20. Ira,G., Malkova,A., Liberi,G., Foiani,M. and Haber,J.E. (2003) Srs2 and Sgs1-Top3 suppress crossovers during double-strand break repair in yeast. Cell, 115, 401–411. 21. Robert,T., Dervins,D., Fabre,F. and Gangloﬀ,S. (2006) Mrc1 and Srs2 are major actors in the regulation of spontaneous crossover. EMBO J., 25, 2837–2846. 22. Liberi,G., Chiolo,I., Pellicioli,A., Lopes,M., Plevani,P., Muzi- Falconi,M. and Foiani,M. (2000) Srs2 DNA helicase is involved in checkpoint response and its regulation requires a functional Mec1- dependent pathway and Cdk1 activity. EMBO J., 19, 5027–5038. 23. Boeke,J.D., LaCroute,F. and Fink,G.R. (1984) A positive selection for mutants lacking orotidine-50-phosphate decarboxylase activity in yeast: 5-ﬂuoro-orotic acid resistance. Mol. Gen. Genet., 197, 345–346. 24. Sherman,F. and Hicks,J. (1991) Micromanipulation and dissection of asci. Methods Enzymol., 194, 21–37. 25. Orr-Weaver,T.L. and Szostak,J.W. (1983) Yeast recombination: the association between double-strand gap repair and crossing-over. Proc. Natl. Acad. Sci. USA, 80, 4417–4421. 26. Broach,J.R., Strathern,J.N. and Hicks,J.B. (1979) Transformation in yeast: development of a hybrid cloning vector and isolation of the CAN1 gene. Gene, 8, 121–133. 27. Pullman,M.E., Penefsky,H.S., Datta,A. and Racker,E. (1960) Partial resolution of the enzymes catalyzing oxidative phosphorylation. I. Puriﬁcation and properties of soluble dinitrophenol-stimulated adenosine triphosphatase. J. Biol. Chem., 235, 3322–3329. 28. Beloin,C., Jeusset,J., Revet,B., Mirambeau,G., Le Hegarat,F. and Le Cam,E. (2003) Contribution of DNA conformation and topol- ogy in right-handed DNA wrapping by the Bacillus subtilis LrpC protein. J. Biol. Chem., 278, 5333–5342. 29. Van Komen,S., Reddy,M.S., Krejci,L., Klein,H. and Sung,P. (2003) ATPase and DNA helicase activities of the Saccharomyces cerevisiae anti-recombinase Srs2. J. Biol. Chem., 278, 44331–44337. 30. Somsen,O.J., Hoeben,M.A., Esgalhado,E., Snoep,J.L., Visser,D., van der Heijden,R.T., Heijnen,J.J. and Westerhoﬀ,H.V. (2000) Glucose and the ATP paradox in yeast. Biochem. J., 352(Pt 2), 593–599. 31. Hoege,C., Pfander,B., Moldovan,G.L., Pyrowolakis,G. and Jentsch,S. (2002) RAD6-dependent DNA repair is linked to modiﬁcation of PCNA by ubiquitin and SUMO. Nature, 419, 135–141. 32. Krejci,L., Macris,M., Li,Y., Van Komen,S., Villemain,J., Ellenberger,T., Klein,H. and Sung,P. (2004) Role of ATP hydrolysis in the antirecombinase function of Saccharomyces cerevisiae Srs2 protein. J. Biol. Chem., 279, 23193–23199. 33. Lopes,M., Foiani,M. and Sogo,J.M. (2006) Multiple mechanisms control chromosome integrity after replication fork uncoupling and restart at irreparable UV lesions. Mol. Cell, 21, 15–27. 34. Palladino,F. and Klein,H.L. (1992) Analysis of mitotic and meiotic defects in Saccharomyces cerevisiae SRS2 DNA helicase mutants. Genetics, 132, 23–37.