A game with many players: Control of gdh transcription in Corynebacterium glutamicum

Glutamate dehydrogenase is a central enzyme connecting nitrogen and carbon metabolism via its precursors ammonium and oxoglutarate and its product glutamate. In Corynebacterium glutamicum glutamate dehydrogenase is especially important, since it is a key enzyme for the biotechnological production of the flavour enhancer l-glutamate. In this study, the regulation of gdh transcription was investigated. While originally described as a constitutively expressed gene, we could show that gdh transcription is highly variable depending on environmental conditions. Regulation of the gdh gene by the C. glutamicum nitrogen control protein AmtR was analyzed in detail in this study.