Temperature and oxygen regulated expression of a glutamine synthetase gene from Vibrio alginolyticus cloned in Escherichia coli.

Glutamine synthetase (GS) synthesis in Vibrio alginolyticus was regulated by temperature, oxygen and nitrogen levels. A GS gene, glnA from V. alginolyticus was cloned on a 5.67 kb insert in the recombinant plasmid pRM210, which enabled Escherichia coli glnA, ntrB, ntrC deletion mutants to utilize (NH4)2SO4 as a sole source of nitrogen. The V. alginolyticus glnA gene was expressed from a regulatory region contained within the cloned fragment. V. alginolyticus glnA expression from pRM210 was subject to regulation by temperature, oxygen and nitrogen levels. GS specific activity in an E. coli wild-type strain was not affected by temperature or oxygen. pRM211 was a deletion derivative of pRM210 and GS production by pRM211 was not regulated by temperature, oxygen or nitrogen levels in E. coli.