A carboxy-terminal 16-amino-acid region of sigma(38) of Escherichia coli is important for transcription under high-salt conditions and sigma activities in vivo.
sigma(38) (or sigma(S), the rpoS gene product) is a sigma subunit of RNA polymerase in Escherichia coli and directs transcription from a number of stationary-phase promoters as well as osmotically inducible promoters. In this study, we analyzed the function of the carboxy-terminal 16-amino-acid region of sigma(38) (residues 315 to 330), which is well conserved among the rpoS gene products of enteric bacterial species. Truncation of this region was shown to result in the loss of sigma activity in vivo using promoter-lacZ fusion constructs, but the mutant sigma(38) retained the binding activity in vivo to the core enzyme. The in vitro transcription analysis revealed that the transcription activity of sigma(38) holoenzyme under high potassium glutamate concentrations was significantly decreased by the truncation of the carboxy-terminal tail element.
Institute of Molecular and Cellular Biosciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-0032, Japan.
M
M
Ohnuma
N
N
Fujita
A
A
Ishihama
K
K
Tanaka
H
H
Takahashi
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D017124:Conserved Sequence; D012321:DNA-Directed RNA Polymerases / Q000737:chemistry / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D019077:Helix-Turn-Helix Motifs; D007700:Kinetics; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry / Q000378:metabolism; D009994:Osmolar Concentration; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D011401:Promoter Regions, Genetic; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012808:Sigma Factor / Q000737:chemistry* / Q000378:metabolism*; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D009838:Oligodeoxyribonucleotides; D010446:Peptide Fragments; D012808:Sigma Factor; C069567:sigma factor KatF protein, Bacteria; D012321:DNA-Directed RNA Polymerases