Kawabata S, Terao Y, Hamada S
Department of Oral Microbiology, Osaka University Faculty of Dentistry, Suita-Osaka, 565-0871 Japan.
Oral Microbiol Immunol. 2000 Feb;15(1):58-62. doi: 10.1034/j.1399-302x.2000.150110.x.
The nucleotide sequence of a Streptococcus mutans serA gene that encodes D-3-phosphoglycerate dehydrogenase has been determined. The gene consisted of 1308-bp nucleotides coding for a 436-amino-acid polypeptide (48,546 Da). The deduced amino acid sequence showed a 66% identity with SerA from Bacillus subtilis and possessed specific residues (G-R-P-N-V-G) in the coenzyme-binding domain, alpha B helix. Recombinant streptococcal SerA was expressed using pMAL-c2 expression vector and purified by amylose resin affinity chromatography and DEAE-Sephacel column chromatography. This SerA enzyme catalyzed detectable reduction of alpha-ketoglutarate to 2-hydroxyglutaric acid. These findings indicate that the novel streptococcal phosphoglycerate dehydrogenase, SerA, is a member of a D-isomer-specific family of 2-hydroxyacid dehydrogenases.
已确定编码D-3-磷酸甘油酸脱氢酶的变形链球菌serA基因的核苷酸序列。该基因由1308个碱基对组成，编码一个436个氨基酸的多肽（48,546道尔顿）。推导的氨基酸序列与枯草芽孢杆菌的SerA有66%的同一性，并且在辅酶结合结构域αB螺旋中具有特定残基（G-R-P-N-V-G）。使用pMAL-c2表达载体表达重组链球菌SerA，并通过直链淀粉树脂亲和色谱和DEAE-葡聚糖凝胶柱色谱进行纯化。这种SerA酶催化了α-酮戊二酸可检测地还原为2-羟基戊二酸。这些发现表明，新型链球菌磷酸甘油酸脱氢酶SerA是2-羟基酸脱氢酶D-异构体特异性家族的一员。
