HMM Summary Page: TIGR02394

FunctionRNA polymerase sigma factor RpoS
Gene SymbolrpoS
Trusted Cutoff378.70
Domain Trusted Cutoff378.70
Noise Cutoff339.75
Domain Noise Cutoff339.75
Isology Typeequivalog
HMM Length285
Mainrole CategoryCellular processes
Subrole CategoryAdaptations to atypical conditions
Gene Ontology TermGO:0006352: transcription initiation, DNA-dependent biological_process
GO:0006950: response to stress biological_process
GO:0016987: sigma factor activity molecular_function
AuthorHaft DH
Entry DateDec 7 2004 10:59AM
Last ModifiedFeb 14 2011 3:27PM
CommentA sigma factor is a DNA-binding protein protein that binds to the DNA-directed RNA polymerase core to produce the holoenzyme capable of initiating transcription at specific sites. Different sigma factors act in vegetative growth, heat shock, extracytoplasmic functions (ECF), etc. This model represents the clade of sigma factors called RpoS (also called sigma-38, KatF, etc.), found only in Proteobacteria. This sigma factor is induced in stationary phase (in response to the stress of nutrient limitation) and becomes the second prinicipal sigma factor at that time. RpoS is a member of the larger Sigma-70 subfamily (TIGR02937) and most closely related to RpoD (TIGR02393).
ReferencesRM 8475100 RT Heterogeneity of the principal sigma factor in Escherichia coli: the rpoS gene product, sigma 38, is a second principal sigma factor of RNA polymerase in stationary-phase Escherichia coli. RA Tanaka K, Takayanagi Y, Fujita N, Ishihama A, Takahashi H. RL Proc Natl Acad Sci U S A. 1993 Apr 15;90(8):3511-5.