3cmt

Mechanism of homologous recombination from the RecA-ssDNA/dsDNA structures

spinqualitylabelsall models 3cmt, resolution 3.15Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3cmt is a 6 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 3.15Å Ligands: ADP, ALF, MG Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function RECA_ECOLI Can catalyze the hydrolysis of ATP in the presence of single-stranded DNA, the ATP-dependent uptake of single-stranded DNA by duplex DNA, and the ATP-dependent hybridization of homologous single-stranded DNAs. It interacts with LexA causing its activation and leading to its autocatalytic cleavage.[HAMAP-Rule:MF_00268] Publication Abstract from PubMed The RecA family of ATPases mediates homologous recombination, a reaction essential for maintaining genomic integrity and for generating genetic diversity. RecA, ATP and single-stranded DNA (ssDNA) form a helical filament that binds to double-stranded DNA (dsDNA), searches for homology, and then catalyses the exchange of the complementary strand, producing a new heteroduplex. Here we have solved the crystal structures of the Escherichia coli RecA-ssDNA and RecA-heteroduplex filaments. They show that ssDNA and ATP bind to RecA-RecA interfaces cooperatively, explaining the ATP dependency of DNA binding. The ATP gamma-phosphate is sensed across the RecA-RecA interface by two lysine residues that also stimulate ATP hydrolysis, providing a mechanism for DNA release. The DNA is underwound and stretched globally, but locally it adopts a B-DNA-like conformation that restricts the homology search to Watson-Crick-type base pairing. The complementary strand interacts primarily through base pairing, making heteroduplex formation strictly dependent on complementarity. The underwound, stretched filament conformation probably evolved to destabilize the donor duplex, freeing the complementary strand for homology sampling. Mechanism of homologous recombination from the RecA-ssDNA/dsDNA structures.,Chen Z, Yang H, Pavletich NP Nature. 2008 May 22;453(7194):489-4. PMID:18497818 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also 3D structures of recombinase A

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