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Protein Domain : IPR012761

Name  RNA polymerase sigma factor RpoS Short Name  RNA_pol_sigma_RpoS
Type  Family Description  The bacterial core RNA polymerase complex, which consists of five subunits, is sufficient for transcription elongation and termination but is unable to initiate transcription. Transcription initiation from promoter elements requires a sixth, dissociable subunit called a sigma factor, which reversibly associates with the core RNA polymerase complex to form a holoenzyme []. RNA polymerase recruits alternative sigma factors as a means of switching on specific regulons. Most bacteria express a multiplicity of sigma factors. Two of these factors, sigma-70 (gene rpoD), generally known as the major or primary sigma factor, and sigma-54 (gene rpoN or ntrA) direct the transcription of a wide variety of genes. The other sigma factors, known as alternative sigma factors, are required for the transcription of specific subsets of genes.With regard to sequence similarity, sigma factors can be grouped into two classes, the sigma-54 and sigma-70 families. Sequence alignments of the sigma70 family members reveal four conserved regions that can be further divided into subregions eg. sub-region 2.2, which may be involved in the binding of the sigma factor to the core RNA polymerase; and sub-region 4.2, which seems to harbor a DNA-binding 'helix-turn-helix' motif involved in binding the conserved -35 region of promoters recognised by the major sigma factors [, ]. This entry 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 principal sigma factor at that time [].

Publication Counts Displayer

0 Child Features

8 Contains

DB identifier Name Short Name Type
IPR011991 Winged helix-turn-helix DNA-binding domain WHTH_DNA-bd_dom Domain
IPR013324 RNA polymerase sigma factor, region 3/4 RNA_pol_sigma_r3_r4 Domain
IPR007627 RNA polymerase sigma-70 region 2 RNA_pol_sigma70_r2 Domain
IPR013325 RNA polymerase sigma factor, region 2 RNA_pol_sigma_r2 Domain
IPR009042 RNA polymerase sigma-70 region 1.2 RNA_pol_sigma70_r1_2 Domain
IPR007630 RNA polymerase sigma-70 region 4 RNA_pol_sigma70_r4 Domain
IPR007624 RNA polymerase sigma-70 region 3 RNA_pol_sigma70_r3 Domain
IPR000943 RNA polymerase sigma-70 RNA_pol_sigma70 Domain

2 Cross References

Identifier
Source . Name

Subject . Primary Identifier
TIGR02394 TIGRFAMs IPR012761
MF_00959 HAMAP IPR012761

2 Data Sets

Name URL
InterPro data set  
InterPro GO Annotation data set  

0 Found In

5 GO Annotation


Subject . Secondary Identifier

Subject . Name

Subject . Symbol

Ontology Term . Identifier

Ontology Term . Name
RNA polymerase sigma factor RpoS   GO:0003677 DNA binding
RNA polymerase sigma factor RpoS   GO:0003700 sequence-specific DNA binding transcription factor activity
RNA polymerase sigma factor RpoS   GO:0016987 sigma factor activity
RNA polymerase sigma factor RpoS   GO:0006352 DNA-templated transcription, initiation
RNA polymerase sigma factor RpoS   GO:0006355 regulation of transcription, DNA-templated

5 Ontology Annotations


Subject . Secondary Identifier

Subject . Name

Subject . Symbol

Ontology Term . Identifier

Ontology Term . Name
RNA polymerase sigma factor RpoS   GO:0003677 DNA binding
RNA polymerase sigma factor RpoS   GO:0003700 sequence-specific DNA binding transcription factor activity
RNA polymerase sigma factor RpoS   GO:0016987 sigma factor activity
RNA polymerase sigma factor RpoS   GO:0006352 DNA-templated transcription, initiation
RNA polymerase sigma factor RpoS   GO:0006355 regulation of transcription, DNA-templated

0 Parent Features

0 Proteins