Mutational analysis of UMP kinase from Escherichia coli
Mutational analysis of UMP kinase from Escherichia coli
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DOI：
10.1128/jb.180.3.473-477.1998
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发表时间：
1998-02-01
影响因子：
3.2
通讯作者：
Bárzu, O
中科院分区：
文献类型：
--
作者：
Bucurenci, N;Serina, L;Bárzu, O
来自大肠杆菌的UMP激酶是参与嘧啶核苷酸从头合成途径的四种调节酶之一。尽管该细菌酶与其他已知的核苷单磷酸激酶没有序列相似性，但氨基酸35 ~ 78和145 ~ 194之间的两个片段分别与磷酸甘油酸激酶和天冬氨酸激酶具有28%和30%的同源性，基于这些相似性，E，选择大肠杆菌UMP激酶进行定点诱变实验。对修饰蛋白进行生化、动力学和光谱分析，确定了催化（Asp146）、结合UMP （Asp174）以及与变构效应物GTP和UTP （Arg62和Asp77）相互作用所必需的残基。
UMP kinase from Escherichia coli is one of the four regulatory enzymes involved in the de novo biosynthetic pathway of pyrimidine nucleotides. This homohexamer, with no counterpart in eukarya, might serve as a target for new antibacterial drugs, Although the bacterial enzyme does not show sequence similarity with any other known nucleoside monophosphate kinase, two segments between amino acids 35 to 78 and 145 to 194 exhibit 28% identity with phosphoglycerate kinase and 30% identity with aspartokinase, respectively, Based on these similarities, a number of residues of E, coli UMP kinase were selected for site-directed mutagenesis experiments. Biochemical, kinetic, and spectroscopic analysis of the modified proteins identified residues essential for catalysis (Asp146), binding of UMP (Asp174), and interaction with the allosteric effecters, GTP and UTP (Arg62 and Asp77).