Protein Family Models

RNA polymerase sigma factor RpoH is involved in regulating the expression of heat shock genes; sigma factors are initiation factors that promote the attachment of RNA polymerase to specific initiation sites and are then released

Date:

2023-03-17

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

A sigma factor is a DNA-binding protein protein that binds to the DNA-directed RNA polymerase core to produce the holoenzyme capable of initiating transcription at specific sites. Different sigma factors act in vegetative growth, heat shock, extracytoplasmic functions (ECF), etc. This model represents the clade of sigma factors called RpoH and further restricted to the Proteobacteria. This protein may be called sigma-32, sigma factor H, heat shock sigma factor, and alternative sigma factor RpoH. Note that in some species the single locus rpoH may be replaced by two or more differentially regulated stress response sigma factors.

Gene:

rpoH

Date:

2024-05-30

Binds with the catalytic core of RNA polymerase to produce the holoenzyme; this sigma factor is responsible for the expression of heat shock promoters

Date:

2021-03-12