Resolution of Holliday junctions in vitro requires the Escherichia coli ruvC gene product.

Connolly, B.; Parsons, C.A.; Benson, F.E.; Dunderdale, H.J.; Sharples, G.J.; Lloyd, R.G.; West, S.C.

Abstract

In previous studies, Holliday junctions generated during RecA-mediated strand-exchange reactions were resolved by fractionated Escherichia coli extracts. We now report the specific binding and cleavage of synthetic Holliday junctions (50 base pairs long) by a fraction purified by chromatography on DEAE-cellulose, phosphocellulose, and single-stranded DNA-cellulose. The cleavage reaction provided a sensitive assay with which to screen extracts prepared from recombination/repair-deficient mutants. Cells with mutations in ruvC lack the nuclease activity that cleaves synthetic Holliday junctions in vitro. This deficiency was restored by a multicopy plasmid carrying a ruvC+ gene that overexpressed junction-resolving activity. The UV sensitivity and deficiency in recombinational repair of DNA exhibited by ruv mutants lead us to suggest that RuvC resolves Holliday junctions in vivo.

Citation

Connolly, B., Parsons, C., Benson, F., Dunderdale, H., Sharples, G., Lloyd, R., & West, S. (1991). Resolution of Holliday junctions in vitro requires the Escherichia coli ruvC gene product. Proceedings of the National Academy of Sciences, 88(14), 6063-6067

• Journal Article Type: Article
• Publication Date: 1991
• Journal: Proceedings of the National Academy of Sciences
• Print ISSN: 0027-8424
• Publisher: National Academy of Sciences
• Volume: 88
• Issue: 14
• Pages: 6063-6067
• Publisher URL: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=1829835