Nitrogen control in Mycobacterium smegmatis: nitrogen-dependent expression of ammonium transport and assimilation proteins depends on the OmpR-type regulator GlnR.
The effect of nitrogen regulation on the level of transcriptional control has been investigated in a variety of bacteria, such as Bacillus subtilis, Corynebacterium glutamicum, Escherichia coli, and Streptomyces coelicolor; however, until now there have been no data for mycobacteria. In this study, we found that the OmpR-type regulator protein GlnR controls nitrogen-dependent transcription regulation in Mycobacterium smegmatis. Based on RNA hybridization experiments with a wild-type strain and a corresponding mutant strain, real-time reverse transcription-PCR analyses, and DNA binding studies using cell extract and purified protein, the glnA (msmeg_4290) gene, which codes for glutamine synthetase, and the amtB (msmeg_2425) and amt1 (msmeg_6259) genes, which encode ammonium permeases, are controlled by GlnR. Furthermore, since glnK (msmeg_2426), encoding a PII-type signal transduction protein, and glnD (msmeg_2427), coding for a putative uridylyltransferase, are in an operon together with amtB, these genes are part of the GlnR regulon as well. The GlnR protein binds specifically to the corresponding promoter sequences and functions as an activator of transcription when cells are subjected to nitrogen starvation.
Amon
Johannes
J
Lehrstuhl für Mikrobiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstr. 5, 91058 Erlangen, Germany.
Bräu
Tanja
T
Grimrath
Aletta
A
Hänssler
Eva
E
Hasselt
Kristin
K
Höller
Martina
M
Jessberger
Nadja
N
Ott
Lisa
L
Szököl
Juraj
J
Titgemeyer
Fritz
F
Burkovski
Andreas
A
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D005816:Genetic Complementation Test; D005974:Glutamate-Ammonia Ligase / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D020102:Mycobacterium smegmatis / Q000235:genetics / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism*; D009713:Nucleotidyltransferases / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D001426:Bacterial Proteins; D027682:Cation Transport Proteins; D009713:Nucleotidyltransferases; D005974:Glutamate-Ammonia Ligase; D009584:Nitrogen