Bacillus subtilis CodY represses early-stationary-phase genes by sensing GTP levels.
CodY, a highly conserved protein in the low G + C, gram-positive bacteria, regulates the expression of many Bacillus subtilis genes that are induced as cells make the transition from rapid exponential growth to stationary phase and sporulation. This transition has been associated with a transient drop in the intracellular pool of GTP. Many stationary-phase genes are also induced during exponential-growth phase by treatment of cells with decoyinine, a GMP synthetase inhibitor. The effect of decoyinine on an early-stationary-phase gene is shown here to be mediated through CodY and to reflect a reduction in guanine nucleotide accumulation. CodY proved to bind GTP in vitro. Moreover, CodY-mediated repression of target promoters was dependent on a high concentration of GTP, comparable to that found in rapidly growing exponential-phase cells. Because a codY-null mutant was able to sporulate under conditions of nutrient excess, CodY also appears to be a critical factor that normally prevents sporulation under such conditions. Thus, B. subtilis CodY is a novel GTP-binding protein that senses the intracellular GTP concentration as an indicator of nutritional conditions and regulates the transcription of early-stationary-phase and sporulation genes, allowing the cell to adapt to nutrient limitation.
Ratnayake-Lecamwasam
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M
Tufts University School of Medicine, Department of Molecular Biology and Microbiology, Boston, Massachusetts 02111, USA.
Serror
P
P
Wong
K W
KW
Sonenshein
A L
AL
D000241:Adenosine / Q000031:analogs & derivatives / Q000378:metabolism; D020816:Amino Acid Motifs; D001412:Bacillus subtilis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D002455:Cell Division / Q000235:genetics; D004268:DNA-Binding Proteins; D015964:Gene Expression Regulation, Bacterial; D006160:Guanosine Triphosphate / Q000378:metabolism*; D008969:Molecular Sequence Data; D009876:Operon; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D013171:Spores, Bacterial
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D012097:Repressor Proteins; C012182:angustmycin A; D006160:Guanosine Triphosphate; D000241:Adenosine