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Activation of σ 28 ‐dependent transcription in Escherichia coli by the cyclic AMP receptor protein requires an unusual promoter organization
Author(s) -
Hollands Kerry,
Lee David J.,
Lloyd Georgina S.,
Busby Stephen J. W.
Publication year - 2010
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.2009.06913.x
Subject(s) - biology , rna polymerase , promoter , microbiology and biotechnology , sigma factor , transcription (linguistics) , transcription factor ii d , activator (genetics) , rna polymerase ii , general transcription factor , camp receptor protein , rna polymerase ii holoenzyme , rna , gene expression , gene , biochemistry , linguistics , philosophy
Summary The Escherichia coli aer regulatory region contains a single promoter that is recognized by RNA polymerase containing the flagellar sigma factor, σ 28 . Expression from this promoter is dependent on direct activation by the cyclic AMP receptor protein, which binds to a target centred 49.5 base pairs upstream from the transcript start. Activator‐dependent transcription from the aer promoter was reconstituted in vitro , and a tethered inorganic nuclease was used to find the position of the C‐terminal domains of the RNA polymerase α subunits in transcriptionally competent open complexes. We report that the ternary activator–RNA polymerase– aer promoter open complex is organized differently from complexes at previously characterized promoters. Among other E. coli promoters recognized by RNA polymerase containing σ 28 , only the trg promoter is activated directly by the cyclic AMP receptor protein. The organization of the different promoter elements and the activator binding site at the trg promoter is the same as at the aer promoter, suggesting a common activation mechanism.