| Literature DB >> 10912000 |
H Nilsen1, I Rosewell, P Robins, C F Skjelbred, S Andersen, G Slupphaug, G Daly, H E Krokan, T Lindahl, D E Barnes.
Abstract
Gene-targeted knockout mice have been generated lacking the major uracil-DNA glycosylase, UNG. In contrast to ung- mutants of bacteria and yeast, such mice do not exhibit a greatly increased spontaneous mutation frequency. However, there is only slow removal of uracil from misincorporated dUMP in isolated ung-/- nuclei and an elevated steady-state level of uracil in DNA in dividing ung-/- cells. A backup uracil-excising activity in tissue extracts from ung null mice, with properties indistinguishable from the mammalian SMUG1 DNA glycosylase, may account for the repair of premutagenic U:G mispairs resulting from cytosine deamination in vivo. The nuclear UNG protein has apparently evolved a specialized role in mammalian cells counteracting U:A base pairs formed by use of dUTP during DNA synthesis.Entities:
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Year: 2000 PMID： 10912000 DOI： 10.1016/s1097-2765(00)80271-3
Source DB: PubMed Journal: Mol Cell ISSN： 1097-2765 Impact factor: 17.970