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B6db references: 12951240

type Journal Article
authors Wada, M.; Nakamori, S.; Takagi, H.
title Serine racemase homologue of Saccharomyces cerevisiae has L-threo-3-hydroxyaspartate dehydratase activity
journal FEMS Microbiol Lett
Activity 4.3.1.16
Family 4.3.1.16
sel selected
ui 12951240
year (2003)
volume 225
number 2
pages 189-93
 
abstract The NH(2)-terminal amino acid sequence of L-threo-3-hydroxyaspartate dehydratase from Pseudomonas sp. T62 showed significant similarity to that of the SRY1 gene product of Saccharomyces cerevisiae (serine racemase in yeast). SRY1 was cloned and expressed in Escherichia coli, and the gene product was purified and partially characterized. The SRY1 gene product exhibited dehydratase activity specific for L-threo-3-hydroxyaspartate (K(m)=3.9 mM, V(max)=110 micromol min(-1) (mg protein)(-1)) but not for D-threo- or DL-erythro-3-hydroxyaspartate. The purified enzyme showed no detectable serine racemase activity. The activity of the enzyme was inhibited by hydroxylamine and EDTA, and was activated by Mg(2+), Ca(2+), and Mn(2+), suggesting that pyridoxal-5'-phosphate and divalent cations participate in the enzyme reaction. Gene disruption and overexpression indicated that SRY1 is responsible for the 3-hydroxyaspartate resistance of S. cerevisiae. To our knowledge, this is the first report of 3-hydroxyaspartate dehydratase activity in eukaryotic cells.
last changed 2009/06/26 15:54

B6db references