PMID: 22537Jan 1, 1978

Ammonia assimilation and glutamate formation in Caulobacter crescentus

Journal of Bacteriology
B ElyRobert A Bender


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.


Jan 1, 1984·Molecular & General Genetics : MGG·S KustuJ C Meeks
Feb 20, 2004·Journal of Bacteriology·Alison K HottesCraig Stephens
Aug 31, 2012·Microbiology and Molecular Biology Reviews : MMBR·Robert A Bender

Related Concepts

Genome Mapping
Enzyme Repression
Genes, Regulator
Glutamate Synthase
Glutamic Acids
Glutamate-Ammonia Ligase
Transduction, Genetic

Trending Feeds


Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Synthetic Genetic Array Analysis

Synthetic genetic arrays allow the systematic examination of genetic interactions. Here is the latest research focusing on synthetic genetic arrays and their analyses.

Neural Activity: Imaging

Imaging of neural activity in vivo has developed rapidly recently with the advancement of fluorescence microscopy, including new applications using miniaturized microscopes (miniscopes). This feed follows the progress in this growing field.

Computational Methods for Protein Structures

Computational methods employing machine learning algorithms are powerful tools that can be used to predict the effect of mutations on protein structure. This is important in neurodegenerative disorders, where some mutations can cause the formation of toxic protein aggregations. This feed follows the latests insights into the relationships between mutation and protein structure leading to better understanding of disease.

Congenital Hyperinsulinism

Congenital hyperinsulinism is caused by genetic mutations resulting in excess insulin secretion from beta cells of the pancreas. Here is the latest research.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Epigenetic Memory

Epigenetic memory refers to the heritable genetic changes that are not explained by the DNA sequence. Find the latest research on epigenetic memory here.

Cell Atlas of the Human Eye

Constructing a cell atlas of the human eye will require transcriptomic and histologic analysis over the lifespan. This understanding will aid in the study of development and disease. Find the latest research pertaining to the Cell Atlas of the Human Eye here.

Femoral Neoplasms

Femoral Neoplasms are bone tumors that arise in the femur. Discover the latest research on femoral neoplasms here.