Ashiuchi M, Packdibamrung K, Miyaji T, Nagata S, Misono H
Research Institute of Molecular Genetics, Kochi University, Japan.
FEMS Microbiol Lett. 1998 Oct 1;167(1):75-80. doi: 10.1111/j.1574-6968.1998.tb13210.x.
D-Threonine dehydrogenase (EC 1.1.1) catalyses the oxidation of the 3-hydroxyl group of D-threonine. The nucleotide sequence of the structural gene, dtdS, for this enzyme from Pseudomonas cruciviae IFO 12047 was determined. The dtdS gene encodes a 292 amino acid polypeptide. The enzyme was overproduced in Escherichia coli cells; the activity was found in cell extracts of the clone. The enzyme showed high sequence similarity to 3-hydroxyisobutyrate dehydrogenases. This is the first example showing the primary structure of an enzyme catalysing the NADP(+)-dependent dehydrogenation of D-threo-3-hydroxyamino acids.
D-苏氨酸脱氢酶（EC 1.1.1）催化D-苏氨酸3-羟基的氧化反应。测定了来自十字花科假单胞菌IFO 12047的该酶结构基因dtdS的核苷酸序列。dtdS基因编码一个含292个氨基酸的多肽。该酶在大肠杆菌细胞中过量表达；在克隆的细胞提取物中发现了活性。该酶与3-羟基异丁酸脱氢酶具有高度的序列相似性。这是首个展示催化D-苏式-3-羟基氨基酸NADP(+)依赖性脱氢反应的酶一级结构的实例。
