ISOLATION OF THE CORYNEBACTERIUM-GLUTAMICUM GLNA GENE ENCODING GLUTAMINE-SYNTHETASE-I

The Corynebacterium glutamicum glutamine synthetase I (GSI) structural gene glnA was cloned by a PCR approach using oligonucleotide primers derived from conserved amino acid sequences of the GSI proteins from v arious bacteria. Disruption or deletion of this gene in C. glutamicum led to a glutamine auxotrophic phenotype and complete loss of glutamin e synthetase activity, indicating the key role of this enzyme in nitro gen metabolism. Additionally, indications for a second glutamine synth etase, GSII, were found.