2abk

REFINEMENT OF THE NATIVE STRUCTURE OF ENDONUCLEASE III TO A RESOLUTION OF 1.85 ANGSTROM

spinqualitylabelsall models 2abk, resolution 1.85Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2abk is a 1 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.85Å Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function END3_ECOLI Has both an apurinic and/or apyrimidinic endonuclease activity and a DNA N-glycosylase activity. Incises damaged DNA at cytosines, thymines and guanines. Acts on a damaged strand, 5' from the damaged site. Required for the repair of both oxidative DNA damage and spontaneous mutagenic 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 1.85 A crystal structure of endonuclease III, combined with mutational analysis, suggests the structural basis for the DNA binding and catalytic activity of the enzyme. Helix-hairpin-helix (HhH) and [4Fe-4S] cluster loop (FCL) motifs, which we have named for their secondary structure, bracket the cleft separating the two alpha-helical domains of the enzyme. These two novel DNA binding motifs and the solvent-filled pocket in the cleft between them all lie within a positively charged and sequence-conserved surface region. Lys120 and Asp138, both shown by mutagenesis to be catalytically important, lie at the mouth of this pocket, suggesting that this pocket is part of the active site. The positions of the HhH motif and protruding FCL motif, which contains the DNA binding residue Lys191, can accommodate B-form DNA, with a flipped-out base bound within the active site pocket. The identification of HhH and FCL sequence patterns in other DNA binding proteins suggests that these motifs may be a recurrent structural theme for DNA binding proteins. Novel DNA binding motifs in the DNA repair enzyme endonuclease III crystal structure.,Thayer MM, Ahern H, Xing D, Cunningham RP, Tainer JA EMBO J. 1995 Aug 15;14(16):4108-20. PMID:7664751 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Endonuclease 3D structures

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