Snedecor B, Chu H, Chen E
Department of Fermentation Research and Process Development, Genetech, Inc., South San Francisco, California 94080.
J Bacteriol. 1991 Oct;173(19):6162-7. doi: 10.1128/jb.173.19.6162-6167.1991.
The gene for the catabolic NAD-linked glutamate dehydrogenase of Peptostreptococcus asaccharolyticus was cloned by selection of Escherichia coli for complementation of a biosynthetic defect. Cloned fragments containing the gene and the P. asaccharolyticus transcription and translation signals are very highly expressed in E. coli. The nucleotide sequence of the cloned gene was determined. It codes for a polypeptide of 421 amino acids, the sequence of which is similar to those of the NADP-accepting glutamate dehydrogenases. The sequence similarity of this protein to the mammalian glutamate dehydrogenases, which accept both NADP and NAD, is greater than its similarity to the bacterial NADP-specific dehydrogenases, suggesting that this NAD-specific bacterial glutamate dehydrogenase and the NADP-specific bacterial dehydrogenases diverged separately from the line leading to the dual-specificity mammalian glutamate dehydrogenases.
通过选择大肠杆菌来互补生物合成缺陷，克隆了不解糖消化链球菌分解代谢型NAD连接的谷氨酸脱氢酶基因。含有该基因以及不解糖消化链球菌转录和翻译信号的克隆片段在大肠杆菌中能非常高效地表达。测定了克隆基因的核苷酸序列。它编码一个由421个氨基酸组成的多肽，其序列与接受NADP的谷氨酸脱氢酶的序列相似。该蛋白与既接受NADP又接受NAD的哺乳动物谷氨酸脱氢酶的序列相似性，大于其与细菌NADP特异性脱氢酶的相似性，这表明这种NAD特异性细菌谷氨酸脱氢酶和NADP特异性细菌脱氢酶是从导致双特异性哺乳动物谷氨酸脱氢酶的谱系中分别分化出来的。
