ABSTRACT
Gene
ytkD
of
Bacillus subtilis
, a member of the Nudix hydrolase superfamily, has been cloned and expressed in
Escherichia coli
. The purified protein has been characterized as a nucleoside triphosphatase active on all of the canonical ribo- and deoxyribonucleoside triphosphates. Whereas all other nucleoside triphosphatase members of the superfamily release inorganic pyrophosphate and the cognate nucleoside monophosphate, YtkD hydrolyses nucleoside triphosphates in a stepwise fashion through the diphosphate to the monophosphate, releasing two molecules of inorganic orthophosphate. Contrary to a previous report, our enzymological and genetic studies indicate that
ytkD
is not an orthologue of
E. coli mutT
.
摘要
基因
ytkD
的
基因 ytkD
是 Nudix水解酶超家族的成员,已被克隆并在
大肠杆菌
.纯化后的蛋白质被鉴定为一种核苷三磷酸酶,对所有典型的核糖核苷和脱氧核糖核苷三磷酸酶都有活性。该超家族的所有其他核苷三磷酸酶成员都会释放出无机焦磷酸和同源的核苷单磷酸,而 YtkD 则以逐步的方式从二磷酸水解到单磷酸,释放出两分子无机正磷酸盐。与之前的报告相反,我们的酶学和遗传学研究表明
ytkD
不是
大肠杆菌 mutT
.