PortEco logo

PMID:20057006

From EcoliWiki
Jump to: navigation, search

Contents

Citation

Kidd, PB and Wingreen, NS (2010) Modeling the role of covalent enzyme modification in Escherichia coli nitrogen metabolism. Phys Biol 7:016006

Abstract

In the bacterium Escherichia coli, the enzyme glutamine synthetase (GS) converts ammonium into the amino acid glutamine. GS is principally active when the cell is experiencing nitrogen limitation, and its activity is regulated by a bicyclic covalent modification cascade. The advantages of this bicyclic-cascade architecture are poorly understood. We analyze a simple model of the GS cascade in comparison to other regulatory schemes and conclude that the bicyclic cascade is suboptimal for maintaining metabolic homeostasis of the free glutamine pool. Instead, we argue that the lag inherent in the covalent modification of GS slows the response to an ammonium shock and thereby allows GS to transiently detoxify the cell, while maintaining homeostasis over longer times.

Links

PubMed Online version:10.1088/1478-3975/55/1/016006

Keywords

Escherichia coli/enzymology; Glutamate-Ammonia Ligase/metabolism; Homeostasis; Models, Biological; Models, Chemical; Nitrogen/metabolism

Significance

You can help EcoliWiki by summarizing why this paper is useful

Useful Materials and Methods

You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.

Annotations

Gene product Qualifier GO ID GO term name Evidence Code with/from Aspect Notes Status

EcoliWiki Links

Add links to pages that link here (e.g. gene, product, method pages)

See also

References

See Help:References for how to manage references in EcoliWiki.