嗜冷菌希瓦氏菌属中冷活性蛋白酪氨酸磷酸酶催化反应所必需的氨基酸残基的鉴定

Specification of amino acid residues essential for the catalytic reaction of cold-active protein-tyrosine phosphatase of a psychrophile, Shewanella sp.

作者信息

Tsuruta Hiroki, Tamura Jun, Yamagata Hiroshi, Aizono Yasuo

机构信息

Center for Cooperative Research and Development, Kobe University, Japan.

出版信息

Biosci Biotechnol Biochem. 2004 Feb;68(2):440-3. doi: 10.1271/bbb.68.440.

DOI:10.1271/bbb.68.440

PMID:14981312

Abstract

Protein-tyrosine phosphatase [EC 3.1.3.48] from a psychrophile, Shewanella sp. shows high activity at low temperatures and has the conserved amino acid sequence of protein-Ser/Thr-phosphatases. Site-directed mutagenesis with the conserved amino acid residues indicated that His148 could be important as a general acid catalyst and Asp115 assists the protonation with His148 of the leaving group of a substrate, and that Asp76 and Asp112 were involved in binding to magnesium ions.

摘要

来自嗜冷菌希瓦氏菌属（Shewanella sp.）的蛋白质酪氨酸磷酸酶[EC 3.1.3.48]在低温下表现出高活性，并且具有蛋白质丝氨酸/苏氨酸磷酸酶的保守氨基酸序列。对保守氨基酸残基进行的定点诱变表明，His148作为一般酸催化剂可能很重要，Asp115协助His148对底物离去基团进行质子化，并且Asp76和Asp112参与与镁离子的结合。