Bacteriophage T4 ????-glucosyltransferase: a novel interaction with gp45 and aspects of the catalytic mechanism

详细信息    查看全文

• 作者：Sommer ; Nicole ; Depping ; Reinhard ; Piotrowski ; Markus ; R??ger ; Wolfgang
• 关键词：Bacteriophage T4 ; ????-Glucosyltransferase ; DNA modification ; Mutagenesis
• 刊名：Biochemical and Biophysical Research Communications
• 出版年：2004
• 出版时间：October 22, 2004
• 年：2004
• 卷：323
• 期：3
• 页码：809-815
• 全文大小：1.59 M

文摘

The bacteriophage T4 ??- and ??-glucosyltransferases (AGT and BGT) catalyse the transfer of glucose from uridine diphosphoglucose to 5-hydroxymethyl cytosine of T4 DNA in an ??- and ??-conformation, respectively. Following the 3D structure of BGT and a secondary structure alignment of AGT and BGT, we performed a site-directed mutagenesis of AGT. A two-domain structure was deduced, with an open substrate-free and a closed substrate-bound conformation. We also identified specific amino acids involved in DNA binding. The identification of a protein???protein interaction of AGT and gp45 which is a part of the T4 replication complex supports the idea that T4 DNA is ??-glucosylated immediately after synthesis. BGT then glucosylates those hydroxymethyl cytosines not previously served by AGT.