Human L-3-phosphoserine phosphatase: sequence, expression and evidence for a phosphoenzyme intermediate.
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.
Collet
J F
JF
Laboratory of Physiological Chemistry, ICP and University of Louvain, Brussels, Belgium.
Gerin
I
I
Rider
M H
MH
Veiga-da-Cunha
M
M
Van Schaftingen
E
E
D000595:Amino Acid Sequence; D000818:Animals; D001419:Bacteria / Q000201:enzymology; D002292:Carcinoma, Renal Cell; D017124:Conserved Sequence; D018076:DNA, Complementary; D006801:Humans; D007680:Kidney Neoplasms; D007700:Kinetics; D008099:Liver / Q000201:enzymology; D008969:Molecular Sequence Data; D010744:Phosphoric Monoester Hydrolases / Q000096:biosynthesis* / Q000737:chemistry* / Q000378:metabolism; D010766:Phosphorylation; D010768:Phosphoserine / Q000378:metabolism; D051381:Rats; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D012550:Schistosoma mansoni / Q000201:enzymology; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014407:Tumor Cells, Cultured
D018076:DNA, Complementary; D010768:Phosphoserine; D010744:Phosphoric Monoester Hydrolases; C022394:phosphoserine phosphatase