Physiological and biochemical characteristics of poly γ-glutamate synthetase complex of Bacillus subtilis
Physiological and biochemical characteristics of poly γ-glutamate synthetase complex of Bacillus subtilis
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DOI：
10.1046/j.0014-2956.2001.02475.x
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发表时间：
2001-10-01
期刊：
影响因子：
--
通讯作者：
Misono, H
中科院分区：
文献类型：
--
作者：
Ashiuchi, M;Nawa, C;Misono, H
研究了枯草芽孢杆菌合成聚谷氨酸(PGA)的酶系统--PgsBCA系统。基因阻断实验表明，该酶系统是枯草杆菌合成PGA的唯一机制。我们成功地实现了在三磷酸腺苷和D-谷氨酸存在下，以产生PgsBCA的大肠杆菌克隆的细胞膜为底物，酶促合成细长的PGA。酶制剂以8 mM CHAPS为底物，在谷氨酸存在下才能催化腺苷二磷酸的形成，D-对映体是最好的共底物，L-对映体次之。对该体系的各个组分PgsB、PGSC和PgsA进行了体外翻译，并对谷氨酸依赖的ATPase反应进行了动力学分析。PGA合成酶复合体PgsBCA是一种非典型的酰胺连接酶。
An enzymatic system for poly gamma -glutamate (PGA) synthesis in Bacillus subtilis, the PgsBCA system, was investigated. The gene-disruption experiment showed that the enzymatic system was the sole machinery of PGA synthesis in B. subtilis. We succeeded in achieving the enzymatic synthesis of elongated PGAs with the cell membrane of the Escherichia coli clone producing PgsBCA in the presence of ATP and D-glutamate. The enzyme preparation solubilized from the membrane with 8 mm Chaps catalyzed ADP-forming ATP hydrolysis only in the presence of glutamate; the D-enantiomer was the best cosubstrate, followed by the L-enantiomer. Each component of the system, PgsB, PgsC, and PgsA, was translated in vitro and the glutamate-dependent ATPase reaction was kinetically analyzed. The PGA synthetase complex, PgsBCA, was suggested to be an atypical amide ligase.