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.
| Original language | English |
|---|---|
| Pages (from-to) | 6063-6067 |
| Number of pages | 5 |
| Journal | PNAS |
| Volume | 88 |
| Issue number | 14 |
| Publication status | Published - 15 Jul 1991 |
Keywords
- Bacterial Proteins
- Bacteriophage phi X 174
- Base Sequence
- DNA Replication
- DNA, Bacterial
- DNA, Viral
- Endodeoxyribonucleases
- Escherichia coli
- Escherichia coli Proteins
- Gene Expression
- Genes, Bacterial
- Molecular Sequence Data
- Oligonucleotide Probes
- Plasmids