Open AccessA stationary phase protein in Escherichia coli with binding activity to the major σ subunit of RNA polymerase
Author(s) -
Miki Jishage,
Akira Ishihama
Publication year - 1998
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.95.9.4953
Subject(s) - rna polymerase , escherichia coli , transcription (linguistics) , protein subunit , biology , sigma factor , microbiology and biotechnology , polymerase , gene , biochemistry , linguistics , philosophy
Switching of the transcription pattern inEscherichia coli during the growth transition from exponential to stationary phase is accompanied by the replacement of the RNA polymerase-associated σ70 subunit (σD ) with σ38 (σS ). A fraction of the σ70 subunit in stationary phase cell extracts was found to exist as a complex with a novel protein, designated Rsd (R egulator ofs igmaD ). The intracellular level of Rsd starts to increase during the transition from growing to stationary phase. Thersd gene was identified at 90 min on theE. coli chromosome. Overexpressed and purified Rsd protein formed complexesin vitro with σ70 but not with other σ subunits, σN , σS , σH , σF , and σE . Analysis of proteolytic fragments of σ70 indicated that Rsd binds at or downstream of region 4, the promoter −35 recognition domain. The isolated Rsd inhibited transcriptionin vitro to various extents depending on the promoters used. We propose that Rsd is a stationary phaseE. coli protein with regulatory activity of the σ70 function.