Previous Article | Next Article ![]()
Journal of Bacteriology, August 2000, p. 4288-4294, Vol. 182, No. 15
Departments of
Microbiology1 and
Biochemistry,3 University of Illinois,
Urbana, Illinois 61801, and Hans-Knöll Institute for
Natural Products Research, 07745 Jena, Germany2
Received 6 March 2000/Accepted 10 May 2000
Cyclopropane fatty acids (CFAs) are generally synthesized as
bacterial cultures enter stationary phase. In Escherichia
coli, the onset of CFA synthesis results from increased
transcription of cfa, the gene encoding CFA synthase.
However, the increased level of CFA synthase activity is transient; the
activity quickly declines to the basal level. We report that the loss
of CFA activity is due to proteolytic degradation dependent on
expression of the heat shock regulon. CFA synthase degradation is
unaffected by mutations in the lon, clpP, and
groEL genes or by depletion of the intracellular ATP pools.
It seems likely that CFA synthase is the target of an unidentified
energy-independent heat shock regulon protease. This seems to be the
first example of heat shock-dependent degradation of a normal
biosynthetic enzyme.
0021-9193/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.
Metabolic Instability of Escherichia
coli Cyclopropane Fatty Acid Synthase Is Due to
RpoH-Dependent Proteolysis
*
Corresponding author. Mailing address: B103 Chemical
and Life Sciences Laboratory, 601 South Goodwin Ave., Urbana, IL 61801. Phone: (217) 333-0425. Fax: (217) 244-6697. E-mail:
j-cronan{at}life.uiuc.edu.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»