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Resolution of Holliday intermediates in recombination and DNA repair: indirect suppression of ruvA, ruvB, and ruvC mutations.

Mandal, T.N.; Mahdi, A.A.; Sharples, G.J.; Lloyd, R.G.

Authors

T.N. Mandal

A.A. Mahdi

R.G. Lloyd



Abstract

The ruvA, ruvB, and ruvC genes of Escherichia coli provide activities that catalyze branch migration and resolution of Holliday junction intermediates in recombination. Mutation of any one of these genes interferes with recombination and reduces the ability of the cell to repair damage to DNA. A suppressor of ruv mutations was identified on the basis of its ability to restore resistance to mitomycin and UV light and to allow normal levels of recombination in a recBC sbcBC strain carrying a Tn10 insertion in ruvA. The mutation responsible was located at 12.5 min on the genetic map and defines a new locus which has been designated rus. The rus suppressor works just as well in recBC sbcA and rec+ sbc+ backgrounds and is not allele specific. Mutations in ruvB and ruvC are suppressed to an intermediate level, except when ruvA is also inactive, in which case suppression is complete. In all cases, suppression depends on RecG protein, a DNA-dependent ATPase that catalyzes branch migration of Holliday junctions. The rus mutation activates an additional factor that probably works with RecG to process Holliday junction intermediates independently of the RuvAB and RuvC proteins. The possibility that this additional factor is a junction-specific resolvase is discussed.

Citation

Mandal, T., Mahdi, A., Sharples, G., & Lloyd, R. (1993). Resolution of Holliday intermediates in recombination and DNA repair: indirect suppression of ruvA, ruvB, and ruvC mutations. Journal of Bacteriology, 175(14), 4325-4334

Journal Article Type Article
Publication Date 1993
Journal Journal of Bacteriology
Print ISSN 0021-9193
Publisher American Society for Microbiology
Volume 175
Issue 14
Pages 4325-4334
Public URL https://durham-repository.worktribe.com/output/1583622
Publisher URL http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=8331065