InterPro : IPR014303

Name  RNA polymerase sigma-70, ECF type Short Name  RNA_pol_sigma-70_ECF
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 group of sigma factors appear by homology, tree building and bidirectional best hits, to represent a conserved family. This entry is found in a limited number of bacterial lineages and includes apparent paralogous expansion in Streptomyces coelicolor(strain A3(2)), and multiple copies in Mycobacterium smegmatis(strain ATCC 700084/mc(2)155), Streptomyces avermitilis MA-4680and Nocardia farcinica IFM 10152.
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Sequence Features

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Proteins

InterPro protein domain ID --> Contigs

 

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0 Child Features

4 Contains

Id Name Short Name Type
IPR013249 RNA polymerase sigma factor 70, region 4 type 2 RNA_pol_sigma70_r4_t2 Domain
IPR013325 RNA polymerase sigma factor, region 2 RNA_pol_sigma_r2 Domain
IPR014284 RNA polymerase sigma-70 like domain RNA_pol_sigma-70_dom Domain
IPR007627 RNA polymerase sigma-70 region 2 RNA_pol_sigma70_r2 Domain

0 Found In

0 Parent Features

3 Publications

First Author Title Year Journal Volume Pages
Helmann JD Structure and function of bacterial sigma factors. 1988 Annu Rev Biochem 57 839-72
Lonetto M The sigma 70 family: sequence conservation and evolutionary relationships. 1992 J Bacteriol 174 3843-9
Gribskov M Sigma factors from E. coli, B. subtilis, phage SP01, and phage T4 are homologous proteins. 1986 Nucleic Acids Res 14 6745-63



To cite PlanMine, please refer to the following publication:

Rozanski, A., Moon, H., Brandl, H., Martín-Durán, J. M., Grohme, M., Hüttner, K., Bartscherer, K., Henry, I., & Rink, J. C.
PlanMine 3.0—improvements to a mineable resource of flatworm biology and biodiversity
Nucleic Acids Research, gky1070. doi:10.1093/nar/gky1070 (2018)