In vitro transcription profiling of the σS subunit of bacterial RNA polymerase: re-definition of the σS regulon and identification of σS-specific promoter sequence elements.

ABSTRACT: Specific promoter recognition by bacterial RNA polymerase is mediated by σ subunits, which assemble with RNA polymerase core enzyme (E) during transcription initiation. However, σ(70) (the housekeeping σ subunit) and σ(S) (an alternative σ subunit mostly active during slow growth) recognize almost identical promoter sequences, thus raising the question of how promoter selectivity is achieved in the bacterial cell. To identify novel sequence determinants for selective promoter recognition, we performed run-off/microarray (ROMA) experiments with RNA polymerase saturated either with σ(70) (Eσ(70)) or with σ(S) (Eσ(S)) using the whole Escherichia coli genome as DNA template. We found that Eσ(70), in the absence of any additional transcription factor, preferentially transcribes genes associated

SUBMITTER: Maciag A 

PROVIDER: S-EPMC3141248 | biostudies-literature | 2011 Jul

REPOSITORIES: biostudies-literature