ubstrate specificities and functional characterization of a hermo-tolerant uracil DNA glycosylase (UdgB) from ycobacterium tuberculosis
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چکیده
Uracil DNA glycosylases (UDGs) excise uracil fromDNA and initiate the base (uracil) excision repair pathway. Ung, a highly conserved protein, is the only UDG characterized so far in mycobacteria. Here, we show that Rv1259 fromMycobacterium tuberculosis codes for a doublestranded DNA (dsDNA) specific UDG (MtuUdgB). MtuUdgB is thermo-tolerant, contains Fe–S cluster and, in addition to uracil, it excises ethenocytosine and hypoxanthine from dsDNA. MtuUdgB is product inhibited by AP-site containing dsDNA but not by uracil. WhileMtuUdgB excises uracil present as a single-nucleotide bulge in dsDNA, it is insensitive to inhibition
منابع مشابه
The uracil DNA glycosylase UdgB of Mycobacterium smegmatis protects the organism from the mutagenic effects of cytosine and adenine deamination.
Spontaneous hydrolytic deamination of DNA bases represents a considerable mutagenic threat to all organisms, particularly those living in extreme habitats. Cytosine is readily deaminated to uracil, which base pairs with adenine during replication, and most organisms encode at least one uracil DNA glycosylase (UDG) that removes this aberrant base from DNA with high efficiency. Adenine deaminates...
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