Identification of genes and gene products whose expression is activated during nitrogen-limited growth in Bacillus subtilis.
The levels of urease and asparaginase were elevated 25- and 20-fold, respectively, in extracts of Bacillus subtilis cells grown in medium containing nitrogen sources that are poor sources of ammonium (NH4+) compared with the levels seen in extracts of cells grown in medium containing nitrogen sources that are good sources of NH4+. To determine whether a collection of genes whose expression responds to nitrogen availability could be isolated, a library of Tn917-lacZ insertions was screened for nitrogen-regulated beta-galactosidase expression. Two fusion strains were identified. beta-Galactosidase expression was 26- and 4,000-fold higher, respectively, in the nrg-21::Tn917-lacZ and the nrg-29::Tn917-lacZ insertion strains during NH4(+)-restricted growth than during growth on nitrogen sources that are good sources of NH4+. PBS1 transduction analysis showed that the nrg-21::Tn917-lacZ insertion mapped between gutB and purB and that the nrg-29::Tn917-lacZ insertion mapped between degSU and spoIID. The repression of expression of these four gene products during growth on good sources of NH4+ required the wild-type glutamine synthetase protein but not the glutamine synthetase regulatory protein, GlnR.
Atkinson
M R
MR
Department of Microbiology, Boston University School of Medicine, Massachusetts 02118.
Fisher
S H
SH
D000641:Ammonia / Q000378:metabolism; D001215:Asparaginase / Q000235:genetics* / Q000378:metabolism; D001412:Bacillus subtilis / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D003433:Crosses, Genetic; D004251:DNA Transposable Elements; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D005838:Genotype; D005974:Glutamate-Ammonia Ligase / Q000235:genetics* / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism*; D011995:Recombination, Genetic; D014161:Transduction, Genetic; D014510:Urease / Q000235:genetics* / Q000378:metabolism; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
D004251:DNA Transposable Elements; D000641:Ammonia; D001616:beta-Galactosidase; D001215:Asparaginase; D014510:Urease; D005974:Glutamate-Ammonia Ligase; D009584:Nitrogen