Hydroxymethyluracil DNA glycosylase in mammalian cells.
نویسندگان
چکیده
منابع مشابه
Hydroxymethyluracil DNA glycosylase in mammalian cells.
An activity has been purified 350-fold from extracts of mouse plasmacytoma cells that forms 5-hydroxymethyluracil (alpha-hydroxythymine) and apyrimidinic sites with phage SPO1 DNA, which contains this base in place of thymine. This DNA glycosylase presumably functions to eliminate hydroxymethyluracil, a major thymine-derived DNA lesion produced by ionizing radiation and oxidative damage. The en...
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Oxanine (Oxa) is a deaminated base lesion derived from guanine in which the N(1)-nitrogen is substituted by oxygen. This work reports the mutagenicity of oxanine as well as oxanine DNA glycosylase (ODG) activities in mammalian systems. Using human DNA polymerase beta, deoxyoxanosine triphosphate is only incorporated opposite cytosine (Cyt). When an oxanine base is in a DNA template, Cyt is effi...
متن کاملExcision of thymine and 5-hydroxymethyluracil by the MBD4 DNA glycosylase domain: structural basis and implications for active DNA demethylation
The mammalian DNA glycosylase--methyl-CpG binding domain protein 4 (MBD4)--is involved in active DNA demethylation via the base excision repair pathway. MBD4 contains an N-terminal MBD and a C-terminal DNA glycosylase domain. MBD4 can excise the mismatched base paired with a guanine (G:X), where X is uracil, thymine or 5-hydroxymethyluracil (5hmU). These are, respectively, the deamination produ...
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V79 cells incorporated 5-hydroxymethyl-2'-deoxyuridine (HmdUrd) into their DNA linearly over a wide range of concentrations and time. Cells grew normally when 0.03% of thymidine residues were replaced with HmdUrd. At this level of substitution, 5-hydroxymethyluracil (HmUra) was removed from DNA at a rate of 30-40%/24 h. Concentrations of HmdUrd in the growth medium which produced higher levels ...
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Some Ts in nuclear DNA of trypanosomes and Leishmania are hydroxylated and glucosylated to yield base J (β-D-glucosyl-hydroxymethyluracil). In Leishmania, about 99% of J is located in telomeric repeats. We show here that most of the remaining J is located at chromosome-internal RNA polymerase II termination sites. This internal J and telomeric J can be reduced by a knockout of J-binding protein...
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ژورنال
عنوان ژورنال: Proceedings of the National Academy of Sciences
سال: 1984
ISSN: 0027-8424,1091-6490
DOI: 10.1073/pnas.81.13.4003