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From Proteopedia
X-ray structure of human ABH2 bound to dsDNA through active site cross-linking
Structural highlights
Function[ALKB2_HUMAN] Dioxygenase that repairs alkylated DNA and RNA containing 1-methyladenine and 3-methylcytosine by oxidative demethylation. Can also repair alkylated DNA containing 1-ethenoadenine (in vitro). Has strong preference for double-stranded DNA. Has low efficiency with single-stranded substrates. Requires molecular oxygen, alpha-ketoglutarate and iron.[1] [2] [3] [4] [5] 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 PubMedEscherichia coli AlkB and its human homologues ABH2 and ABH3 repair DNA/RNA base lesions by using a direct oxidative dealkylation mechanism. ABH2 has the primary role of guarding mammalian genomes against 1-meA damage by repairing this lesion in double-stranded DNA (dsDNA), whereas AlkB and ABH3 preferentially repair single-stranded DNA (ssDNA) lesions and can repair damaged bases in RNA. Here we show the first crystal structures of AlkB-dsDNA and ABH2-dsDNA complexes, stabilized by a chemical cross-linking strategy. This study reveals that AlkB uses an unprecedented base-flipping mechanism to access the damaged base: it squeezes together the two bases flanking the flipped-out one to maintain the base stack, explaining the preference of AlkB for repairing ssDNA lesions over dsDNA ones. In addition, the first crystal structure of ABH2, presented here, provides a structural basis for designing inhibitors of this human DNA repair protein. Crystal structures of DNA/RNA repair enzymes AlkB and ABH2 bound to dsDNA.,Yang CG, Yi C, Duguid EM, Sullivan CT, Jian X, Rice PA, He C Nature. 2008 Apr 24;452(7190):961-5. PMID:18432238[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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