期刊
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
卷 295, 期 2, 页码 508-514出版社
ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI: 10.1016/S0006-291X(02)00705-2
关键词
hyperthermophile; archaea; PTPase; substrate trapping; phosphatase
The Tk-ptp gene encoding a protein tyrosine phosphatase from the hyperthermophilic archaeon Thermococcus kodakaraensis KOD1 was cloned and biochemical characteristics of the recombinant protein (Tk-PTP) were examined. A series of mutants, D63A (replacing Asp-63 with Ala), C93S, C93A, R99K, and R99M, were also constructed and analyzed. Two unique features were found. First, the Tk-PTP showed the phosphatase activity not only toward phosphotyrosine but also toward phosphoserine. Second, the conserved Asp-63, which corresponds to a critical residue among other known PTPs, was not essential for catalysis. Cys-93 and Arg-99 residues played a crucial role in substrate binding and catalysis. To know a specific substrate for Tk-PTP, C93S mutant was used to trap substrate proteins from cell extract of KOD1 Phenylalanyl-tRNA synthetase subunit P-chain, one of the gene products of RNA terminal phosphate cyclase operon and phosphomannomutase, was identified, suggesting that they functioned for phosphate donation. (C) 2002 Elsevier Science (USA). All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据