|
type |
Journal Article |
authors |
Ito T, Hemmi H, Kataoka K, Mukai Y, Yoshimura T. |
title |
A novel zinc-dependent D-serine dehydratase from Saccharomyces cerevisiae |
journal |
Biochem J |
Activity |
4.3.1.18 |
Family |
4.3.1.18.b |
sel |
selected |
ui |
17937657 |
year |
(2008) |
volume |
409 |
number |
2 |
pages |
399-406 |
| |
abstract |
YGL196W of Saccharomyces cerevisiae encodes a putative protein that is unidentified but is predicted to have a motif similar to that of the N-terminal domain of the bacterial alanine racemase. In the present study 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 recombinant Escherichia coli cells depends on pyridoxal 5'-phosphate and zinc, and catalyses the conversion of D-serine into pyruvate and ammonia with the K(m) and k(cat) 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 approx. 3 and 2% of D-serine respectively. L-Serine, L-threonine and beta-Cl-L-alanine are inert as substrates. Atomic absorption analysis revealed that the enzyme contains one zinc atom per enzyme monomer. The enzyme activities toward D-serine and D-threonine were decreased by EDTA treatment and recovered by the addition of Zn2+. Little recovery was observed with Mg2+, Mn2+, Ca2+, Ni2+, Cu2+, K+ or Na+. In contrast, the activity towards beta-Cl-D-alanine was retained after EDTA treatment. These results suggest that zinc is involved in the elimination of the hydroxy 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. |
last changed |
2011/01/19 18:20 |
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