Abstract
Glutamine synthetase (GS), encoded by glnA, is a key enzyme in ammonia assimilation in diverse species. In enteric bacteria, four proteins are involved in the nitrogen regulation of glnA transcription. The uridylyltransferase (UTase) is the primary nitrogen sensor. The small trimeric protein PII, encoded by glnB, is an intracellular signal transmitter which coordinates the response of the Ntr system to the N-status of the cell. Under conditions of nitrogen limitation the UTase covalently modifies PII by uridylylation. The signal which stimulates the sensing system is based on the concentration ratio of regulatory metabolites. UTase activity is inhibited by glutamine, whereas a-ketoglutarate and ATP bound to PII protein, modify its allosteric properties facilitating its uridylylation. The two other proteins, NtrB, a histidine kinase, and NtrC the transcriptional activator of glnA, belong to a two component regulatory system. In addition of the regulation of GS biosynthesis, the activity of GS is also modified by reversible adenylylation according to the cell-N status (reviewed by Magasanik, 1996).
Keywords
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
This is a preview of subscription content, log in via an institution.
Buying options
Tax calculation will be finalised at checkout
Purchases are for personal use only
Learn about institutional subscriptionsPreview
Unable to display preview. Download preview PDF.
References
Allikmets RB et al. (1993) Gene 136, 231–236.
de Zamaroczy M (1995) In Fendrik I, ed., Azospirillum VI; NATO ASI series G, vol. 37, pp. 77–89, Springer Verlag, Berlin.
de Zamaroczy M et al. (1993) J. Bacteriol. 175, 2507–2515.
de Zamaroczy M et al. (1996) J. Bacteriol. 178, 4143–4149.
Liu J, Magasanik B (1993) J. Bacteriol. 175, 7441–7449.
Magasanik B (1996) In Neidhardt FC, ed., E. coli and Salmonella Cellular and Molecular Biology, pp. 1344–1356, ASM Press, Washington D.C.
van Heeswijk WC et al. (1996) Mol. Microbiol. 21, 133–146.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1998 Springer Science+Business Media Dordrecht
About this chapter
Cite this chapter
de Zamaroczy, M., Elmerich, C. (1998). Regulatory Roles of the Structural Homologues PII and Pz Proteins in Azospirillum brasilense . In: Elmerich, C., Kondorosi, A., Newton, W.E. (eds) Biological Nitrogen Fixation for the 21st Century. Current Plant Science and Biotechnology in Agriculture, vol 31. Springer, Dordrecht. https://doi.org/10.1007/978-94-011-5159-7_35
Download citation
DOI: https://doi.org/10.1007/978-94-011-5159-7_35
Publisher Name: Springer, Dordrecht
Print ISBN: 978-94-010-6169-8
Online ISBN: 978-94-011-5159-7
eBook Packages: Springer Book Archive