3djl
From Proteopedia
Crystal structure of alkylation response protein E. coli AidB
Structural highlights
Function[AIDB_ECOLI] Part of the adaptive DNA-repair response to alkylating agents. Could prevent alkylation damage by protecting DNA and destroying alkylating agents that have yet to reach their DNA target. Binds to double-stranded DNA with a preference for a DNA region that includes its own promoter. Shows weak isovaleryl-CoA dehydrogenase activity in vitro.[1] [2] [3] 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 PubMedExposure of Escherichia coli to alkylating agents activates expression of AidB in addition to DNA repair proteins Ada, AlkA, and AlkB. AidB was recently shown to possess a flavin adenine dinucleotide (FAD) cofactor and to bind to dsDNA, implicating it as a flavin-dependent DNA repair enzyme. However, the molecular mechanism by which AidB acts to reduce the mutagenic effects of specific DNA alkylators is unknown. We present a 1.7-A crystal structure of AidB, which bears superficial resemblance to the acyl-CoA dehydrogenase superfamily of flavoproteins. The structure reveals a unique quaternary organization and a distinctive FAD active site that provides a rationale for AidB's limited dehydrogenase activity. A highly electropositive C-terminal domain not present in structural homologs was identified by mutational analysis as the DNA binding site. Structural analysis of the DNA and FAD binding sites provides evidence against AidB-catalyzed DNA repair and supports a model in which AidB acts to prevent alkylation damage by protecting DNA and destroying alkylating agents that have yet to reach their DNA target. Structure and DNA binding of alkylation response protein AidB.,Bowles T, Metz AH, O'Quin J, Wawrzak Z, Eichman BF Proc Natl Acad Sci U S A. 2008 Oct 7;105(40):15299-304. Epub 2008 Sep 30. PMID:18829440[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
| ||||||||||||||||||||
