>TIGR02980 SigBFG RNA polymerase sigma-70 factor, sigma-B/F/G subfamily; InterPro: IPR014322 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 recognized by the major sigma factors , . This group of similar sigma-70 factors includes clades found in Bacilli (including the sporulation factors SigF:IPR014236 from INTERPRO and SigG:IPR014212 from INTERPRO as well as SigB:IPR014288 from INTERPRO), and the high GC Gram-positive bacteria (Actinobacteria) where a variable number of them are found depending on the lineage.; GO: 0003677 DNA binding, 0003700 transcription factor activity, 0016987 sigma factor activity, 0006352 transcription initiation, 0006355 regulation of transcription DNA-dependent.

Probab=92.43  E-value=0.094  Score=30.11  Aligned_cols=45  Identities=33%  Similarity=0.380  Sum_probs=39.0

Q ss_pred             CCCCHHHHHHHHH-HHCCCCHHHHHHHHCCCHHHHHHHHHHHHHHH
Q ss_conf             8889779999999-98599979999994999889999999999980
Q gi|254780694|r  184 FELTGREVECLTW-ISEGKTSDEIAVILGISRNTVNNYIASIMRKT  228 (246)
Q Consensus       184 ~~LT~RE~eVl~l-ia~G~t~~eIA~~L~iS~~TV~~hl~~i~~KL  228 (246)
T Consensus       179 ~~LpeRER~il~lRFf~~~TQ~eiA~~lGiSQMhVSRl~~~~L~~L  224 (229)
T TIGR02980       179 AALPERERRILLLRFFEDKTQSEIAERLGISQMHVSRLLRRALKRL  224 (229)
T ss_pred             HHCCHHHCEEEEEEEECCCCHHHHHHHCCCCHHHHHHHHHHHHHHH
T ss_conf             5079027076100010697789999781843678899999999999