ruvC
Domain
Each subunit has a cleft approximately 20-25 Angstroms wide and 20 Angstroms deep, which is sufficient to accommodate dsDNA. Residues thought to be catalytically important (Asp-8, Glu-67, Asp-139 and Asp-142) line this cleft.
Function
The RuvA-RuvB-RuvC complex processes Holliday junctions during genetic recombination and DNA repair (PubMed:6374379). Endonuclease that resolves Holliday junction (HJ) intermediates. Cleaves cruciform DNA by making single-stranded nicks across the junction at symmetrical positions within the homologous arms, leaving a 5'-phosphate and a 3'-hydroxyl group; requires a central core of homology in the junction (PubMed:10471285, PubMed:1661673, PubMed:1758493, PubMed:1829835, PubMed:36000732, PubMed:8001122, PubMed:8106500, PubMed:8195150, PubMed:9000618, PubMed:9135161, PubMed:9160752). The consensus cleavage sequence is 5'-(A/T)TT(C>G/A)-3'. Cleavage occurs on the 3'-side of the TT dinucleotide at the point of strand exchange, although there is some flexibility in the position cleaved (PubMed:10471285, PubMed:8001122, PubMed:8195150, PubMed:9135161). The cleavage reactions can be uncoupled; incision requires the presence of two consensus cleavage sequences, although they do not have to be identical (PubMed:9135161). The presence of a 5'-phosphate in a half-cut site accelerates cleavage of the second site, ensuring the second cleavage occurs within the lifetime of a single RuvC-HJ complex (PubMed:19399178). Binds to cruciform DNA in a sequence non-specific manner (PubMed:10471285, PubMed:8106500, PubMed:8195150).
An in vitro resolvase system that forms and processes HJ has been reconstituted with DNA substrates, RuvA, RuvB and RuvC. RuvA-RuvB increases the rate of strand exchange (branch migration), dissociates the RecA filament and allows RuvC to cleave in both orientations at the cruciform junction (PubMed:10421637, PubMed:9160752). HJ-RuvA-RuvB-RuvC complexes resolve Holliday junctions and also undergo branch migration, providing evidence for a coupled branch migration/HJ resolution reaction (PubMed:10421637).
Sequence Similarities
Belongs to the RuvC family.
Cellular localization
- Cytoplasm
- In 15% of cell localizes to discrete nucleoid foci (probable DNA damage sites) upon treatment with mitomycin C (MMC) for 2 hours.
Alternative names
b1863, JW1852, ruvC, Crossover junction endodeoxyribonuclease RuvC, Holliday junction endonuclease RuvC, Holliday junction nuclease RuvC, Holliday junction resolvase RuvC