1mwi
Crystal structure of a MUG-DNA product complex
Structural highlights
FunctionMUG_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.[1] [2] 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 PubMedG:U mismatches resulting from deamination of cytosine are the most common promutagenic lesions occurring in DNA. Uracil is removed in a base-excision repair pathway by uracil DNA-glycosylase (UDG), which excises uracil from both single- and double-stranded DNA. Recently, a biochemically distinct family of DNA repair enzymes has been identified, which excises both uracil and thymine, but only from mispairs with guanine. Crystal structures of the mismatch-specific uracil DNA-glycosylase (MUG) from E. coli, and of a DNA complex, reveal a remarkable structural and functional homology to UDGs despite low sequence identity. Details of the MUG structure explain its thymine DNA-glycosylase activity and the specificity for G:U/T mispairs, which derives from direct recognition of guanine on the complementary strand. Crystal structure of a G:T/U mismatch-specific DNA glycosylase: mismatch recognition by complementary-strand interactions.,Barrett TE, Savva R, Panayotou G, Barlow T, Brown T, Jiricny J, Pearl LH Cell. 1998 Jan 9;92(1):117-29. PMID:9489705[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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