6lw3
From Proteopedia
Crystal structure of RuvC from Pseudomonas aeruginosa
Structural highlights
FunctionRUVC_PSEAE The RuvA-RuvB-RuvC complex processes Holliday junction (HJ) DNA during genetic recombination and DNA repair. Endonuclease that resolves HJ intermediates. Cleaves cruciform DNA by making single-stranded nicks across the HJ at symmetrical positions within the homologous arms, yielding a 5'-phosphate and a 3'-hydroxyl group; requires a central core of homology in the junction. The consensus cleavage sequence is 5'-(A/T)TT(C/G)-3'. Cleavage occurs on the 3'-side of the TT dinucleotide at the point of strand exchange. HJ branch migration catalyzed by RuvA-RuvB allows RuvC to scan DNA until it finds its consensus sequence, where it cleaves and resolves the cruciform DNA.[HAMAP-Rule:MF_00034] Complements an E.coli deletion mutant (PubMed:8982068). A C-terminally truncated protein (residues 1-153) binds cruciform but not linear dsDNA, the consensus cleavage sequence is 5'-TT|C-3' (PubMed:32085896).[1] [2] Publication Abstract from PubMedThe Holliday junction, a four-way DNA structure, is an important intermediate of homologous recombination. Proper Holliday junction resolution is critical to complete the recombination process. In most bacterial cells, the Holliday junction cleavage is mainly performed by a specific endonuclease RuvC. Here, we describe the biochemical properties and the crystal structure of RuvC from an opportunistic pathogen, Pseudomonas aeruginosa (PaRuvC). PaRuvC specifically binds to the Holliday junction DNA and preferentially cleaves it at the consensus 5'-TTC-3'. PaRuvC uses Mg(2+) as the preferred divalent metal cofactor for Holliday junction cleavage and its optimum pH is 8.0-9.0. Elevated temperatures (37-60 degrees C) boost the catalytic activity, but temperatures higher than 53 degrees C reduce the protein stability. The crystal structure of PaRuvC determined at 2.4 A and mutagenesis analysis reveal key residues involved in the dimer formation, substrate binding and catalysis. Our results are expected to provide useful information to combat antibiotic resistance of Pseudomonas aeruginosa by targeting its homologous recombination system. Biochemical and structural characterization of the Holliday junction resolvase RuvC from Pseudomonas aeruginosa.,Hu Y, He Y, Lin Z Biochem Biophys Res Commun. 2020 Apr 30;525(2):265-271. doi:, 10.1016/j.bbrc.2020.02.062. Epub 2020 Feb 19. PMID:32085896[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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