Journal of Bacteriology, November 2001, p. 6422-6428, Vol. 183, No. 21
0021-9193/01/$04.00+0 DOI: 10.1128/JB.183.21.6422-6428.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
/
Hydrolase Is Required for Energy
Stress Activation of the
B Transcription Factor in
Bacillus subtilis
andDepartment of Food Science and Technology, University of California, Davis, California 95616
Received 11 June 2001/Accepted 10 August 2001
The general stress response of Bacillus subtilis is
controlled by the
B transcription factor, which is
activated in response to diverse energy and environmental stresses.
These two classes of stress are transmitted by separate signaling
pathways which converge on the direct regulators of
B,
the RsbV anti-anti-
factor and the RsbW anti-
factor. The energy
signaling branch involves the RsbP phosphatase, which dephosphorylates RsbV in order to trigger the general stress response. The
rsbP structural gene lies downstream from
rsbQ in a two-gene operon. Here we identify the RsbQ
protein as a required positive regulator inferred to act in concert
with the RsbP phosphatase. RsbQ bound RsbP in the yeast two-hybrid
system, and a large in-frame deletion in rsbQ had the
same phenotype as a null allele of rsbP
an inability to
activate
B in response to energy stress. Genetic
complementation studies indicated that this phenotype was not due to a
polar effect of the rsbQ alteration on
rsbP. The predicted rsbQ product is a
hydrolase or acyltransferase of the
/
fold superfamily, members
of which catalyze a wide variety of reactions. Notably, substitutions
in the presumed catalytic triad of RsbQ also abolished the energy stress response but had no detectable effect on RsbQ structure, synthesis, or stability. We conclude that the catalytic activity of
RsbQ is an essential constituent of the energy stress signaling pathway.
Present address: MJ Research, Inc., South San Francisco, CA 94080.
This article has been cited by other articles:
| Appl. Environ. Microbiol. | Infect. Immun. | Eukaryot. Cell |
|---|---|---|
| Mol. Cell. Biol. | J. Virol. | Microbiol. Mol. Biol. Rev. |
| ALL ASM JOURNALS |