This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ely, B Articles by Bender, R A Search for Related Content PubMed PubMed Citation Articles by Ely, B Articles by Bender, R A

Ammonia assimilation and glutamate formation in Caulobacter crescentus.

ABSTRACT

In the dimorphic bacterium Caulobacter crescentus, ammonia assimilation occurs only via the combined action of the enzymes glutamine synthetase and glutamate synthase. Mutants auxotrophic for glutamate lacked glutamate synthase activity, and the mutations leading to the glutamate auxotrophy appeared to lie at two distinct genetic loci. Both glutamate synthase and glutamine synthetase activities were subject to regulation by repression. Glutamate synthase activity was highest in cultures grown in minimal medium with ammonia as sole nitrogen source and was about fivefold lower in rich broth. Glutamine synthetase activity was highest in cells grown with growth-rate-limiting amounts of ammonia as nitrogen source and was about fourfold lower in rich broth. In addition, glutamine synthetase activity appeared to be regulated by an adenylylation system like that described for Escherichia coli.

This article has been cited by other articles:

• Hottes, A. K., Meewan, M., Yang, D., Arana, N., Romero, P., McAdams, H. H., Stephens, C. (2004). Transcriptional Profiling of Caulobacter crescentus during Growth on Complex and Minimal Media. J. Bacteriol. 186: 1448-1461 [Abstract] [Full Text]