Methyl- and Normal-Cytosine Deamination by the Foreign DNA Restriction Enzyme APOBEC3A
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چکیده
Multiple studies have indicated that the TET oxidases and, more controversially, the AID/APOBEC deaminases have the capacity to convert genomic DNA 5methylcytosine (MeC) into altered nucleobases that provoke excision repair and culminate in the replacement of the original MeC with a normal cytosine (C). We show that human APOBEC3A (A3A) efficiently deaminates both MeC to thymine (T) and normal C to uracil (U) in singlestranded DNA substrates. In comparison, the related enzyme APOBEC3G (A3G) has undetectable MeC-to-T activity and 10-fold less Cto-U activity. Upon 100-fold induction of endogenous A3A by interferon, the MeC status of bulk chromosomal DNA is unaltered whereas both MeC and C nucleobases in transfected http://www.jbc.org/cgi/doi/10.1074/jbc.M112.385161 The latest version is at JBC Papers in Press. Published on August 15, 2012 as Manuscript M112.385161
منابع مشابه
Biochemical analysis of hypermutation by the deoxycytidine deaminase APOBEC3A.
APOBEC3A belongs to a family of single-stranded DNA (ssDNA) DNA cytosine deaminases that are known for restriction of HIV through deamination-induced mutational inactivation, e.g. APOBEC3G, or initiation of somatic hypermutation and class switch recombination (activation-induced cytidine deaminase). APOBEC3A, which is localized to both the cytoplasm and nucleus, not only restricts HIV but can a...
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