1pu8

Crystal structure of H.pylori 3-methyladenine DNA glycosylase (MagIII) bound to 1,N6-ethenoadenine

spinqualitylabelsall models 1pu8, resolution 2.13Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1pu8 is a 2 chain structure with sequence from Helicobacter pylori. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.13Å Ligands: BME, EA1, KCX Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function O25323_HELPY DNA repair enzyme that has both DNA N-glycosylase activity and AP-lyase activity (By similarity).[PIRNR:PIRNR001435] 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 DNA glycosylases catalyze the excision of chemically modified bases from DNA. Although most glycosylases are specific to a particular base, the 3-methyladenine (m3A) DNA glycosylases include both highly specific enzymes acting on a single modified base, and enzymes with broader specificity for alkylation-damaged DNA. Our structural understanding of these different enzymatic specificities is currently limited to crystal and NMR structures of the unliganded enzymes and complexes with abasic DNA inhibitors. Presented here are high-resolution crystal structures of the m3A DNA glycosylase from Helicobacter pylori (MagIII) in the unliganded form and bound to alkylated bases 3,9-dimethyladenine and 1,N6-ethenoadenine. These are the first structures of a nucleobase bound in the active site of a m3A glycosylase belonging to the helix-hairpin-helix superfamily. MagIII achieves its specificity for positively-charged m3A not by direct interactions with purine or methyl substituent atoms, but rather by stacking the base between two aromatic side chains in a pocket that excludes 7-methylguanine. We report base excision and DNA binding activities of MagIII active site mutants, together with a structural comparison of the HhH glycosylases. Crystal structures of 3-methyladenine DNA glycosylase MagIII and the recognition of alkylated bases.,Eichman BF, O'Rourke EJ, Radicella JP, Ellenberger T EMBO J. 2003 Oct 1;22(19):4898-909. PMID:14517230 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also DNA glycosylase 3D structures

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