YGL196W of Saccharomyces cerevisiae encodes a putative protein that is unidentified but predicted to have a motif similar to that of the N-terminal domain of the bacterial alanine racemase. We found that YGL196W encodes a novel D-serine dehydratase, which belongs to a different protein family from that of the known bacterial enzyme. The yeast D-serine dehydratase purified from the recombinant E. coli cells depends on pyridoxal phosphate and zinc, and catalyzes the conversion of D-serine to pyruvate and ammonia with the Km and kcat values of 0.39 mM and 13.1 s -1, respectively. D-Threonine and beta-Cl-D-alanine also serve as substrates with catalytic efficiencies which are about 3 and 2% of D-serine, respectively. L-Serine, L-threonine, and beta-Cl-L-alanine are inert as a substrate. The atomic absorption analysis revealed that the enzyme contains 1.0 Zn atom per enzyme monomer. The enzyme activities toward D-serine and D-threonine were decreased by the EDTA treatment and recovered by the addition of Zn 2+. Little recovery was observed with Mg 2+, Mn 2+, Ca 2+, Ni 2+, Cu 2+, K +, or Na +. In contrast, the activity towards beta-Cl-D-alanine was retained after the EDTA treatment. These results suggest that zinc is involved in the elimination of the hydroxyl group of D-serine and D-threonine. D-Serine dehydratase of S. cerevisiae is probably the first example of a eukaryotic D-serine dehydratase and that of a specifically zinc-dependent pyridoxal enzyme as well.
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|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Reference||Annotation Extension|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Conditions||Strain||Source||Reference|