Protein Family Models

Region 4 of sigma-70 like sigma-factors are involved in binding to the -35 promoter element via a helix-turn-helix motif [1]. [1]. 11931761. Structure of the bacterial RNA polymerase promoter specificity sigma subunit. Campbell EA, Muzzin O, Chlenov M, Sun JL, Olson CA, Weinman O, Trester-Zedlitz ML, Darst SA;. Mol Cell 2002;9:527-539. (from Pfam)

Date:

2024-10-16

These proteins are probably RNA polymerase sigma factors belonging to the extra-cytoplasmic function (ECF) subfamily [1] and show sequence similarity to Pfam:PF04542 and Pfam:PF04545. [1]. 12073657. The extracytoplasmic function (ECF) sigma factors. Helmann JD;. Adv Microb Physiol 2002;46:47-110. (from Pfam)

Date:

2024-10-16

This HMM hits a core region shared by multiple sigma factors, interchangeable subunits that complete the RNA polymerase holoenzyme and allow transcription to start. In E. coli K-12 alone, this HMM hits RpoD (sigma-70), RpoH (sigma-32), FliA (sigma-28), FecI (sigma-19), RpoS, and RpoE.

Date:

2024-10-16

FecI is an RNA polymerase (RNAP) sigma factor, that is of the ECF (sigma-70) type that works specifically in enabling transcription of the fec (ferric citrate uptake) operon. Sigma factors are interchangeable adapter subunits of the RNAP holoenzyme. The activity of ECF (extracytoplasmic function) sigma factors may be modulated by membrane-spanning regulatory factors that undergo cleave in response to conditions sensed outside the plasma membrane. FecI is regulated by the sigma factor regulator FecR, which has pro-sigma but reportedly also anti-sigma factor activity.

Gene:

fecI

Date:

2023-05-09

This model encompasses all varieties of the sigma-70 type sigma factors including the ECF subfamily. A number of sigma factors have names with a different number than 70 (i.e. sigma-38), but in fact, all except for the Sigma-54 family (TIGR02395) are included within this family. Several PFAM models hit segments of these sequences including Sigma-70 region 2 (PF04542) and Sigma-70, region 4 (PF04545), but not always above their respective trusted cutoffs.

Date:

2024-06-27

Date:

2020-10-26

Date:

2020-10-26