期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1989
卷号：86
期号：22
页码：8877-8881
DOI：10.1073/pnas.86.22.8877
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Mutations in the mutY gene of Escherichia coli confer hypermutability reflecting G.C to T.A transversion mutations and result in a deficiency in methyl-independent G-A to G.C mismatch correction. In the present work, the mutY product has been purified to near homogeneity by virtue of its ability to restore G-A to G.C mismatch correction to cell-free extracts of a mutS mutY strain. The 36-kDa protein renders the strand containing the mispaired adenine labile to base-catalyzed cleavage and sensitive to cleavage by several apurinic/apyrimidinic-site endonucleases, with the sites of strand scission by both agents corresponding to the location of the mismatch. These findings indicate that MutY is a DNA glycosylase that hydrolyzes the glycosyl bond linking the mis-paired adenine to deoxyribose. MutY, a 5'-apurinic/apyrimidinic-site endonuclease, DNA polymerase I, and DNA ligase are sufficient to reconstitute MutY-dependent G-A to G.C repair in vitro.
