Abstract
Recent evidence suggests that the regulation of intracellular glutamate levels could play an important role in the ability of pathogenic slow-growing mycobacteria to grow in vivo. However, little is known about the in vitro requirement for the enzymes which catalyse glutamate production and degradation in the slow-growing mycobacteria, namely; glutamine oxoglutarate aminotransferase (GOGAT) and glutamate dehydrogenase (GDH), respectively. We report that allelic replacement of the Mycobacterium bovis BCG gltBD-operon encoding for the large (gltB) and small (gltD) subunits of GOGAT with a hygromycin resistance cassette resulted in glutamate auxotrophy and that deletion of the GDH encoding-gene (gdh) led to a marked growth deficiency in the presence of L-glutamate as a sole nitrogen source as well as reduction in growth when cultured in an excess of L-asparagine.
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Ammonium Compounds / metabolism
-
Culture Media / chemistry
-
Glutamate Dehydrogenase / metabolism*
-
Glutamic Acid / metabolism
-
Mycobacterium bovis / enzymology
-
Mycobacterium bovis / growth & development
-
Mycobacterium bovis / metabolism*
-
Nitrogen / metabolism*
-
Protein Subunits / metabolism
-
Transaminases / metabolism*
Substances
-
Ammonium Compounds
-
Culture Media
-
Protein Subunits
-
Glutamic Acid
-
Glutamate Dehydrogenase
-
Transaminases
-
Nitrogen
Grants and funding
The study was supported financially by the Department of Biomedical Sciences, Division of Molecular Biology and Human Genetics,Stellenbosch University. AJV received a bursary from the the National Research Foundation (DAAD-NRF). The financial assistance of the National Research Foundation (DAAD-NRF) towards this research is hereby acknowledged. Opinions expressed and conclusions arrived at, are those of the author and are not necessarily to be attributed to the DAAD-NRF. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.