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An analogue of the DnaJ molecular chaperone whose expression is controlled by σ S during the stationary phase and phosphate starvation in Escherichia coli
Author(s) -
Yamashino Takafumi,
Kakeda Minoru,
Ueguchi Chiharu,
Mizuno Takeshi
Publication year - 1994
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.1994.tb00442.x
Subject(s) - biology , escherichia coli , chaperone (clinical) , escherichia coli proteins , stationary phase , phosphate , starvation , microbiology and biotechnology , genetics , biochemistry , gene , medicine , pathology , chemistry , chromatography , endocrinology
Summary The Escherichia coli CbpA protein appears to be an analogue of the molecular chaperone, DnaJ, as judged from not only its structure but also its possible function. The expression of cbpA , however, was not significantly affected by up‐shift of the growth temperature. Remarkably, it was found that the expression of cbpA was induced under certain growth conditions, such as the entry of cells into stationary phase, or growth in a phosphate‐limited medium. Such conditional expression of cbpA was regulated at the transcriptional level in a σ S ‐dependent manner. The structure of this σ S ‐dependent cbpA promoter was clarified by determining its transcription start site. The cbpA promoter region was found to contain an unusual DNA structure (i.e. DNA curvature). From these results, it was suggested that, in contrast to DnaJ, CbpA may function as a molecular chaperone in an adaptive response to environmental stresses other than heat shock.