2d7d
Structural insights into the cryptic DNA dependent ATP-ase activity of UvrB
Structural highlights
FunctionUVRB_BACSU The UvrABC repair system catalyzes the recognition and processing of DNA lesions. A damage recognition complex composed of 2 UvrA and 2 UvrB subunits scans DNA for abnormalities. Upon binding of the UvrA(2)B(2) complex to a putative damaged site, the DNA wraps around one UvrB monomer. DNA wrap is dependent on ATP binding by UvrB and probably causes local melting of the DNA helix, facilitating insertion of UvrB beta-hairpin between the DNA strands. Then UvrB probes one DNA strand for the presence of a lesion. If a lesion is found the UvrA subunits dissociate and the UvrB-DNA preincision complex is formed. This complex is subsequently bound by UvrC and the second UvrB is released. If no lesion is found, the DNA wraps around the other UvrB subunit that will check the other stand for damage (By similarity). Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe UvrABC pathway is a ubiquitously occurring mechanism targeted towards the repair of bulky base damage. Key to this process is UvrB, a DNA-dependent limited helicase that acts as a lesion recognition element whilst part of a tracking complex involving UvrA, and as a DNA-binding platform required for the presentation of damage to UvrC for subsequent processing. We have been able to determine the structure of a ternary complex involving UvrB* (a C-terminal truncation of full-length UvrB), a polythymine trinucleotide and ADP. This structure has highlighted the roles of key conserved residues in DNA binding distinct from those of the beta-hairpin, where most of the attention in previous studies has been focussed. We are also the first to report the structural basis underlying conformational re-modelling of the beta-hairpin that is absolutely required for DNA binding and how this event results in an ATPase primed for catalysis. Our data provide the first insights at the molecular level into the transformation of UvrB into an active helicase. Structural insights into the cryptic DNA-dependent ATPase activity of UvrB.,Eryilmaz J, Ceschini S, Ryan J, Geddes S, Waters TR, Barrett TE J Mol Biol. 2006 Mar 17;357(1):62-72. Epub 2006 Jan 6. PMID:16426634[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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