Human l-3-phosphoserine phosphatase: sequence, expression and evidence for a phosphoenzyme intermediate

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• 作者：Collet ; Jean-Franç ; ois ; Gerin ; Isabelle ; Rider ; Mark H. ; Veiga-da-Cunha ; Maria ; Van Schaftingen ; Emile
• 刊名：FEBS Letters
• 出版年：1997
• 出版时间：May 26, 1997
• 年：1997
• 卷：408
• 期：3
• 页码：281-284
• 全文大小：730 K

文摘

We report the sequence of the cDNA encoding human l-3-phosphoserine phosphatase. The encoded polypeptide contains 225 residues and shows 30 % sequence identity with the Escherichia coli enzyme. The human protein was expressed in a bacterial expression system and purified. Similar to known l-3-phosphoserine phosphatases, it catalyzed the Mg²⁺-dependent hydrolysis of l-phosphoserine and an exchange reaction between l-serine and l-phosphoserine. In addition we found that the enzyme was phosphorylated upon incubation with l-[³²P]phosphoserine, which indicates that the reaction mechanism proceeds via the formation of a phosphoryl-enzyme intermediate. The sensitivity of the phosphoryl-enzyme to alkali and to hydroxylamine suggests that an aspartyl- or a glutamyl-phosphate was formed. The nucleotide sequence of the cDNA described in this article has been deposited in the EMBL data base under accession number Y10275.