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Differential inhibition of transcription from σ 70 ‐ and σ 32 ‐dependent promoters by rifampicin
Author(s) -
Węgrzyn Alicja,
Szalewska-Pałasz Agnieszka,
Błaszczak Adam,
Liberek Krzysztof,
Węgrzyn Grzegorz
Publication year - 1998
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(98)01449-5
Subject(s) - rna polymerase , transcription (linguistics) , microbiology and biotechnology , protein subunit , escherichia coli , rifampicin , biology , promoter , polymerase , rna polymerase ii , sigma factor , chemistry , biochemistry , enzyme , gene , antibiotics , gene expression , linguistics , philosophy
Rifampicin is an antibiotic which binds to the β subunit of prokaryotic RNA polymerases and prevents initiation of transcription. It was found previously that production of heat shock proteins in Escherichia coli cells after a shift from 30°C to 43°C is not completely inhibited by this antibiotic. Here we demonstrate that while activity of a p L ‐ lacZ fusion ( p L is a σ 70 ‐dependent promoter) in E. coli cells is strongly inhibited by rifampicin, a p groE ‐ lacZ fusion, whose activity is dependent on the σ 32 factor, retains significant residual activity even at relatively high rifampicin concentrations. Differential sensitivity to this antibiotic of RNA polymerase holoenzymes containing either the σ 70 or the σ 32 subunit was confirmed in vitro. Since the effects of an antibiotic that binds to the β subunit can be modulated by the presence of either the σ 70 or the σ 32 subunit in the holoenzyme, it is tempting to speculate that binding of various σ factors to the core of RNA polymerase results in different conformations of particular holoenzymes, including changes in the core enzyme.