A second DNA methyltransferase repair enzyme in Escherichia coli.
A second DNA methyltransferase repair enzyme in Escherichia coli.
复制标题
大肠杆菌中的第二种 DNA 甲基转移酶修复酶。
DOI：
10.1073/pnas.85.9.3039
复制
发表时间：
1988
影响因子：
11.1
通讯作者：
Samson,L
中科院分区：
文献类型：
--
作者：
Rebeck,GW;Coons,S;Carroll,P;Samson,L
大肠杆菌ada-alkB操纵子编码一个39-kDa的蛋白质（Ada），它是一种DNA修复甲基转移酶和一个27-kDa的蛋白质（AlkB）的未知功能。DNA印迹杂交分析表明，烷基化敏感的E。coli突变体BS 23 [Sedgwick，B. & Lindahl，T.等人（1982）J. Mol. 154，169-175]是缺失整个ada-alkB操纵子的缺失突变体。尽管缺乏ada基因及其产物，但细胞含有可检测水平的DNA修复甲基转移酶活性。我们的结论是，在BS 23细胞中的甲基转移酶是一个基因的产品比ADA。在大肠杆菌的ada-10：：Tn 10插入突变体的提取物中检测到类似的活性。coli AB 1157。这种DNA甲基转移酶的分子量约为19 kDa，转移DNA中O 6-甲基鸟嘌呤和O 4-甲基胸腺嘧啶的甲基，但不转移甲基磷酸三酯损伤的甲基。这种酶不被低剂量的烷化剂诱导，并且在ada+和许多ada-E中以低水平表达。大肠杆菌菌株。
The Escherichia coli ada-alkB operon encodes a 39-kDa protein (Ada) that is a DNA-repair methyltransferase and a 27-kDa protein (AlkB) of unknown function. By DNA blot hybridization analysis we show that the alkylation-sensitive E. coli mutant BS23 [Sedgwick, B. & Lindahl, T. (1982) J. Mol. Biol. 154, 169-175] is a deletion mutant lacking the entire ada-alkB operon. Despite the absence of the ada gene and its product, the cells contain detectable levels of a DNA-repair methyltransferase activity. We conclude that the methyltransferase in BS23 cells is the product of a gene other than ada. A similar activity was detected in extracts of an ada-10::Tn10 insertion mutant of E. coli AB1157. This DNA methyltransferase has a molecular mass of about 19 kDa and transfers the methyl groups from O6-methylguanine and O4-methylthymine in DNA, but not those from methyl phosphotriester lesions. This enzyme was not induced by low doses of alkylating agent and is expressed at low levels in ada+ and a number of ada- E. coli strains.
影响因子：
4.3
作者：
H. Sambrook
通讯作者：
H. Sambrook