TY - JOUR
T1 - Stationary-phase-inducible ''gearbox'' promoters
T2 - Differential effects of katF mutations and role of σ70
AU - Bohannon, D. E.
AU - Connell, N.
AU - Keener, J.
AU - Tormo, A.
AU - Espinosa-Urgel, M.
AU - Zambrano, M. M.
AU - Kolter, R.
PY - 1991
Y1 - 1991
N2 - Many of the changes in gene expression observed when Escherichia coli cells enter stationary phase are regulated at the level of transcription initiation. A group of stationary-phase-inducible promoters, known as ''gearbox'' promoters, display a characteristic sequence in the -10 region which differs greatly from the consensus sequence for σ70-dependent promoters. Here we describe our studies on the gearbox promoters bolAp1 and mcbAp, responsible for the temporally regulated transcription of bolA and the genes involved in the synthesis of the peptide antibiotic microcin B17, respectively. Deletion analysis of mcbAp demonstrated that the stationary-phase-inducible properties of this promoter are found in a DNA fragment extending from -54 to +11 bp, surrounding the transcriptional start site, and are separable from DNA sequences responsible for the OmpR-dependent stimulation of transcription of mcbAp. In vitro transcription studies indicate that the RNA polymerase holoenzyme involved in the transcription of mcbAp contains σ70. In this and an accompanying paper (R. Lange and R. Hengge-Aronis, J. Bacteriol. 173:4474-4481, 1991), experiments are described which show that the product of katF, a global regulator of stationary-phase gene expression and a putative sigma factor, is required for the expression of bolAp1 fused to the reporter gene lacZ. In contrast, mcbAp appears to be negatively regulated by katF. We discuss the implications of these results for postexponential gene expression and the role of gearbox sequences in the regulation of promoter activity.
AB - Many of the changes in gene expression observed when Escherichia coli cells enter stationary phase are regulated at the level of transcription initiation. A group of stationary-phase-inducible promoters, known as ''gearbox'' promoters, display a characteristic sequence in the -10 region which differs greatly from the consensus sequence for σ70-dependent promoters. Here we describe our studies on the gearbox promoters bolAp1 and mcbAp, responsible for the temporally regulated transcription of bolA and the genes involved in the synthesis of the peptide antibiotic microcin B17, respectively. Deletion analysis of mcbAp demonstrated that the stationary-phase-inducible properties of this promoter are found in a DNA fragment extending from -54 to +11 bp, surrounding the transcriptional start site, and are separable from DNA sequences responsible for the OmpR-dependent stimulation of transcription of mcbAp. In vitro transcription studies indicate that the RNA polymerase holoenzyme involved in the transcription of mcbAp contains σ70. In this and an accompanying paper (R. Lange and R. Hengge-Aronis, J. Bacteriol. 173:4474-4481, 1991), experiments are described which show that the product of katF, a global regulator of stationary-phase gene expression and a putative sigma factor, is required for the expression of bolAp1 fused to the reporter gene lacZ. In contrast, mcbAp appears to be negatively regulated by katF. We discuss the implications of these results for postexponential gene expression and the role of gearbox sequences in the regulation of promoter activity.
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U2 - 10.1128/jb.173.14.4482-4492.1991
DO - 10.1128/jb.173.14.4482-4492.1991
M3 - Article
C2 - 1906064
AN - SCOPUS:0025772545
SN - 0021-9193
VL - 173
SP - 4482
EP - 4492
JO - Journal of bacteriology
JF - Journal of bacteriology
IS - 14
ER -