Differential inhibition of transcription from sigma(70)- and sigma(32)-dependent promoters by rifampicin

Citation
A. Wegrzyn et al., Differential inhibition of transcription from sigma(70)- and sigma(32)-dependent promoters by rifampicin, FEBS LETTER, 440(1-2), 1998, pp. 172-174
Citations number
16
Categorie Soggetti
Biochemistry & Biophysics
Journal title
FEBS LETTERS
ISSN journal
00145793 → ACNP
Volume
440
Issue
1-2
Year of publication
1998
Pages
172 - 174
Database
ISI
SICI code
0014-5793(19981127)440:1-2<172:DIOTFS>2.0.ZU;2-5
Abstract
Rifampicin is an antibiotic which binds to the beta subunit of prokaryotic RNA polymerases and prevents initiation of transcription, It was found prev iously that production of heat shock proteins in Escherichia coli cells aft er a shift from 30 degrees C to 43 degrees C is not completely inhibited by this antibiotic, Here we demonstrate that while activity of a p(L)-lacZ fu sion (p(L) is a sigma(70)-dependent promoter) in E. coli cells is strongly inhibited by rifampicin, a p(groE)-lacZ fusion, whose activity is dependent on the sigma(32) factor, retains significant residual activity even at rel atively high rifampicin concentrations. Differential sensitivity to this an tibiotic of RNA polymerase holoenzymes containing either the sigma(70) or t he sigma(32) subunit was confirmed in vitro, Since the effects of an antibi otic that binds to the beta subunit can be modulated by the presence of eit her the sigma(70) or the sigma(32) subunit in the holoenzyme, it is temptin g to speculate that binding of various a factors to the core of RNA polymer ase results in different conformations of particular holoenzymes, including changes in the core enzyme. (C) 1998 Federation of European Biochemical So cieties.