Purification and characterization of a novel enzyme, L-threo-3-hydroxyaspartate dehydratase, from Pseudomonas sp. T62.
L-threo-3-Hydroxyaspartate dehydratase (L-threo-3-hydroxyaspartate hydro-lyase), which exhibited specificity for L-threo-3-hydroxyaspartate (K(m)=0.74 mM, V(max)=37.5 micromol min(-1) (mg protein)(-1)) but not for D-threo or D, L-erythro-3-hydroxyaspartate, was purified from a cell-free extract of Pseudomonas sp. T62. The activity of the enzyme was inhibited by hydroxylamine and EDTA, which suggests that pyridoxal 5'-phosphate and divalent cations participate in the enzyme reaction. The NH(2)-terminal amino acid sequence showed significant similarity to the Saccharomyces cerevisiae YKL218c gene product, a hypothetical threonine dehydratase. However, the purified enzyme showed no threonine dehydratase activity.
Wada
M
M
Department of Bioscience, Fukui Prefectural University, 4-1-1 Kenjyojima, Matsuoka-cho, Fukui, Japan.
Matsumoto
T
T
Nakamori
S
S
Sakamoto
M
M
Kataoka
M
M
Liu
J Q
JQ
Itoh
N
N
Yamada
H
H
Shimizu
S
S
D000595:Amino Acid Sequence; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D006836:Hydro-Lyases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry; D011549:Pseudomonas / Q000201:enzymology*; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012988:Soil Microbiology; D013379:Substrate Specificity
D010446:Peptide Fragments; D006836:Hydro-Lyases; C122119:L-threo-3-hydroxyaspartate dehydratase