Lipase of Staphylococcus hyicus: analysis of the catalytic triad by site-directed mutagenesis.

In this study the putative catalytic triad Ser-His-Asp of the Staphylococcus hyicus ssp. hyicus lipase was investigated. Putative catalytic sites determined by homology comparisons of three staphylococcal and other non-staphylococcal lipases were altered by site-directed mutagenesis. Since the mutations did not influence the secretion of the lipase, the decrease in lipase activity of the mutants strongly supports the proposed involvement of Ser369 and His600 in catalysis. Asp559 is postulated to be the third amino acid of the triad.