1p7m

SOLUTION STRUCTURE AND BASE PERTURBATION STUDIES REVEAL A NOVEL MODE OF ALKYLATED BASE RECOGNITION BY 3-METHYLADENINE DNA GLYCOSYLASE I

spinqualitylabelsall models 1p7m Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1p7m is a 1 chain structure with sequence from Escherichia coli. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Solution NMR Ligands: ADK, ZN Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function 3MG1_ECOLI Hydrolysis of the deoxyribose N-glycosidic bond to excise 3-methyladenine from the damaged DNA polymer formed by alkylation lesions. 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 PubMed The specific recognition mechanisms of DNA repair glycosylases that remove cationic alkylpurine bases in DNA are not well understood partly due to the absence of structures of these enzymes with their cognate bases. Here we report the solution structure of 3-methyladenine DNA glycosylase I (TAG) in complex with its 3-methyladenine (3-MeA) cognate base, and we have used chemical perturbation of the base in combination with mutagenesis of the enzyme to evaluate the role of hydrogen bonding and pi-cation interactions in alkylated base recognition by this DNA repair enzyme. We find that TAG uses hydrogen bonding with heteroatoms on the base, van der Waals interactions with the 3-Me group, and conventional pi-pi stacking with a conserved Trp side chain to selectively bind neutral 3-MeA over the cationic form of the base. Discrimination against binding of the normal base adenine is derived from direct sensing of the 3-methyl group, leading to an induced-fit conformational change that engulfs the base in a box defined by five aromatic side chains. These findings indicate that base specific recognition by TAG does not involve strong pi-cation interactions, and suggest a novel mechanism for alkylated base recognition and removal. Solution structure and base perturbation studies reveal a novel mode of alkylated base recognition by 3-methyladenine DNA glycosylase I.,Cao C, Kwon K, Jiang YL, Drohat AC, Stivers JT J Biol Chem. 2003 Nov 28;278(48):48012-20. Epub 2003 Sep 16. PMID:13129925 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also DNA glycosylase 3D structures

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