A pathway branching in transcription initiation in Escherichia coli.
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.
Structural Biology Center, National Institute of Genetics, The Graduate University for Advanced Studies, Mishima, Shizuoka, Japan.
Motoki
M
Susa
Tomoko
T
Kubori
Nobuo
N
Shimamoto
D000693:Anaerobiosis / Q000235:genetics; D001483:Base Sequence; D015536:Down-Regulation; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000502:physiology*; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D014158:Transcription, Genetic; D035602:Transcriptional Elongation Factors
D029968:Escherichia coli Proteins; C079668:GreA protein, E coli; C079667:GreB protein, E coli; D014157:Transcription Factors; D035602:Transcriptional Elongation Factors