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Protein Domain : IPR017848

Name  RNA polymerase sigma factor, RpoD-like, cyanobacteria Short Name  RNA_pol_sigma_RpoD_cyanobac
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 family includes a number of closely related sigma-70 () factors in the cyanobacteria. All appear most closely related to the essential sigma-70 factor RpoD, and some are related to the RpoD C-terminal domain model ().

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

1 Cross References

Source . Name

Subject . Primary Identifier
TIGR02997 TIGRFAMs IPR017848

1 Data Sets

Name URL
InterPro data set  

0 Found In

0 GO Annotation

0 Ontology Annotations

0 Parent Features

0 Proteins