Metabolic Modeling Tutorial
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Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
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Caulobacter crescentus CB15 Pathway: ammonia assimilation cycle III

If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.

Locations of Mapped Genes:

Synonyms: ammonia assimilation III, GS/GOGAT pathway

Superclasses: Degradation/Utilization/Assimilation Inorganic Nutrients Metabolism Nitrogen Compounds Metabolism Ammonia Assimilation
Superpathways

Summary:
Escherichia coli K-12 can synthesize L-glutamate from ammonia in two pathways. In addition, if complex sources of nitrogen are available, other pathways become active and take over glutamate synthesis.

In the first pathway L-glutamate is synthesized directly from ammonia, 2-oxoglutarate, and NADPH, as described in glutamate biosynthesis III.

The other pathway, which is described here, is a cyclic pathway, which consists of two steps.

In the first step L-glutamine is synthesized from ammonia and L-glutamate in an ATP-requiring reaction.

ammonium + L-glutamate + ATP → L-glutamine + ADP + phosphate + H+ (EC 6.3.1.2)

In the second step the amido group is transferred from L-glutamine to 2-oxoglutarate yielding two molecules of L-glutamate.

2 L-glutamate + NADP+ ← L-glutamine + 2-oxoglutarate + NADPH + H+ (EC 1.4.1.13)

Because glutamine biosynthesis utilizes one molecule of glutamate and the second reaction yields 2 molecules of glutamate, these two reactions function as a cycle, each turn of which utilizes one molecule each of ammonia, ATP, NADPH, and 2-oxoglutarate, and produces one molecule of L-glutamate.

This pathway is active in energy-rich (glucose-containing), nitrogen-poor environments.

Subpathways: glutamate biosynthesis I , glutamine biosynthesis I

Credits:
Created in MetaCyc 02-Dec-1998 by Pellegrini-Toole A , Marine Biological Laboratory
Imported from MetaCyc 18-Sep-2013 by Fulcher CA , SRI International


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Page generated by SRI International Pathway Tools version 18.5 on Fri Dec 19, 2014, BIOCYC14B.