Riba L, Becerril B, Servín-González L, Valle F, Bolivar F
Departamento de Biología Molecular, Universidad Nacional Autónoma de México, Morelos.
Gene. 1988 Nov 30;71(2):233-46. doi: 10.1016/0378-1119(88)90040-6.
Glutamate dehydrogenase (GDH) catalyzes the synthesis of L-glutamate from 2-oxoglutarate and ammonia. The complete nucleotide sequence of the Escherichia coli gdhA gene, as well as its 5' and 3' flanking regions have been previously reported [Valle et al., Gene 23 (1983) 199-209; 27 (1984) 193-199]. In this paper we present data on the GDH specific activities using both excess and limiting concentrations of ammonia as nitrogen sources. Evidence is presented on the regulation of the mRNA levels for this enzyme by the ammonia concentration in the growth medium. We have identified a single and apparently invariant transcript for several metabolic growth conditions. We also report the identification of a functional promoter and the corresponding transcription start point under several growth conditions. Finally, possible regulatory sequences located at the 5' flanking region of the gdhA gene are discussed.
谷氨酸脱氢酶（GDH）催化从2-氧代戊二酸和氨合成L-谷氨酸。大肠杆菌gdhA基因的完整核苷酸序列及其5'和3'侧翼区域此前已有报道[瓦莱等人，《基因》23（1983年）199 - 209；27（1984年）193 - 199]。在本文中，我们展示了以过量和有限浓度的氨作为氮源时GDH的比活性数据。文中给出了生长培养基中氨浓度对该酶mRNA水平调控的证据。我们已经确定了几种代谢生长条件下的单一且明显不变的转录本。我们还报告了在几种生长条件下功能性启动子和相应转录起始点的鉴定。最后，讨论了位于gdhA基因5'侧翼区域的可能调控序列。
