Positive regulator of glutamate biosynthesis (gltAB genes). Negatively regulates its own expression. Activated by alpha-ketoglutarate and inhibited by glutamate and by RocG. Interacts with gutamate dehydrogenase RocG. Induced by glucose, repressed by arginine, less protein accumulates when grown in the presence of glucose and arginine (at protein level). Belongs to the LysR transcriptional regulatory family.