4zyd
From Proteopedia
Crystal structure of Sulfolobus solfataricus O6-methylguanine methyltransferase in complex with modified DNA
Structural highlights
FunctionOGT_SACS2 Involved in the cellular defense against the biological effects of O6-methylguanine (O6-MeG) and O4-methylthymine (O4-MeT) in DNA. Repairs the methylated nucleobase in DNA by stoichiometrically transferring the methyl group to a cysteine residue in the enzyme. This is a suicide reaction: the enzyme is irreversibly inactivated.[HAMAP-Rule:MF_00772] Publication Abstract from PubMedAlkylated DNA-protein alkyltransferases repair alkylated DNA bases, which are among the most common DNA lesions, and are evolutionary conserved, from prokaryotes to higher eukaryotes. The human ortholog, hAGT, is involved in resistance to alkylating chemotherapy drugs. We report here on the alkylated DNA-protein alkyltransferase, SsOGT, from an archaeal species living at high temperature, a condition that enhances the harmful effect of DNA alkylation. The exceptionally high stability of SsOGT gave us the unique opportunity to perform structural and biochemical analysis of a protein of this class in its post-reaction form. This analysis, along with those performed on SsOGT in its ligand-free and DNA-bound forms, provides insights in the structure-function relationships of the protein before, during and after DNA repair, suggesting a molecular basis for DNA recognition, catalytic activity and protein post-reaction fate, and giving hints on the mechanism of alkylation-induced inactivation of this class of proteins. Structure-function relationships governing activity and stability of a DNA alkylation damage repair thermostable protein.,Perugino G, Miggiano R, Serpe M, Vettone A, Valenti A, Lahiri S, Rossi F, Rossi M, Rizzi M, Ciaramella M Nucleic Acids Res. 2015 Jul 30. pii: gkv774. PMID:26227971[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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