1mwj

Crystal Structure of a MUG-DNA pseudo substrate complex

spinqualitylabelsall models 1mwj, resolution 2.85Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1mwj is a 2 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 2.85Å Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function MUG_ECOLI Excises ethenocytosine and uracil, which can arise by alkylation or deamination of cytosine, respectively, from the corresponding mispairs with guanine in ds-DNA. It is capable of hydrolyzing the carbon-nitrogen bond between the sugar-phosphate backbone of the DNA and the mispaired base. The complementary strand guanine functions in substrate recognition. Required for DNA damage lesion repair in stationary-phase cells. 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 bacterial mismatch-specific uracil-DNA glycosylase (MUG) and eukaryotic thymine-DNA glycosylase (TDG) enzymes form a homologous family of DNA glycosylases that initiate base-excision repair of G:U/T mismatches. Despite low sequence homology, the MUG/TDG enzymes are structurally related to the uracil-DNA glycosylase enzymes, but have a very different mechanism for substrate recognition. We have now determined the crystal structure of the Escherichia coli MUG enzyme complexed with an oligonucleotide containing a non-hydrolysable deoxyuridine analogue mismatched with guanine, providing the first structure of an intact substrate-nucleotide productively bound to a hydrolytic DNA glycosylase. The structure of this complex explains the preference for G:U over G:T mispairs, and reveals an essentially non-specific pyrimidine-binding pocket that allows MUG/TDG enzymes to excise the alkylated base, 3, N(4)-ethenocytosine. Together with structures for the free enzyme and for an abasic-DNA product complex, the MUG-substrate analogue complex reveals the conformational changes accompanying the catalytic cycle of substrate binding, base excision and product release. Crystal structure of a thwarted mismatch glycosylase DNA repair complex.,Barrett TE, Scharer OD, Savva R, Brown T, Jiricny J, Verdine GL, Pearl LH EMBO J. 1999 Dec 1;18(23):6599-609. PMID:10581234 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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