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A pathway branching in transcription initiation in Escherichia coli
Author(s) -
Susa Motoki,
Kubori Tomoko,
Shimamoto Nobuo
Publication year - 2006
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.1365-2958.2006.05058.x
Subject(s) - biology , promoter , rna polymerase , transcription (linguistics) , gene , escherichia coli , genetics , transcription factor , rna polymerase ii , dna , microbiology and biotechnology , gene expression , linguistics , philosophy
Summary In transcription initiation, all RNA polymerase molecules bound to a promoter have been conventionally supposed to proceed into elongation of transcript. However, for Escherichia coli RNA polymerase, evidence has been accumulated for a view that only its fraction can proceed into elongation and the rest is retained at a promoter in non‐productive form: a pathway branching in transcription initiation. Proteins such as GreA and GreB affect these fractions at several promoters in vitro . To reveal the ubiquitous existence of the branched mechanism in E. coli , we searched for candidate genes whose transcription decreased by disruption of greA and greB using a DNA array. Among the arbitrarily selected 11 genes from over 100, the atpC , cspA and rpsA passed the test by Northern blotting. The Gre factors activated transcription initiation from their promoters in vitro , and the results demonstrated that the branched mechanism is exploited in vivo regulation. Consistently, decrease in the level of the GreA in an anaerobic stationary condition accompanied a decrease in the levels of transcripts of these genes.