General description: Members of this group are only present in Proteobacteria and have homology to proteins from the original group ECF43 (100%). Interestingly, this group has an ECF σ factor domain (Pfam: Sigma70_ECF) instead of the σ2 and σ4 domains that typically appear in other groups.
Special features: Proteins from ECF43 are associated with protein kinases encoded in position +1, which have been proposed to be part of the regulatory mechanism in original ECF43 (Staroń et al., 2009). These kinases contain one transmembrane helix (87.8%) and extracytoplasmic tetratricopeptide repeats. Interestingly, the first part of the σ2.2 region, which contains a DAED motif involved in core RNAP binding (Wilson & Lamont, 2006), is substituted by S/T residues in members of ECF43. It is possible that this is the phosphorylation site of the protein kinase encoded in +1, which will replace the missing negative charges.
Genomic context conservation: Other than the protein kinase, genetic contexts of members of ECF43s1 contain a conserved formamidopyrimidine-DNA glycosylase in position -1 and a transposase fused to a fatty acid desaturase.
Promoter motif conservation: The predicted target promoter motifs contain a conserved GTC in -35 and a CAG in -10.
Summary: ECF43 has a different sequence, which might impair the retrieval of more proteins of this type. Members of this group could be phosphorylated by a conserved protein kinase encoded in +1. The putative phosphorylation site could be located in an S/T rich area that substitutes the negatively-charged motif that binds to the core RNAP in σ2.2.
Number of representative ECFs: 75
Number of non-redundant ECFs: 69
Sequences with C-terminal extension: 0.00%
Sequences with N-terminal extension: 0.00%
Overrepresented class: Gammaproteobacteria [49.33%]
|Mutational analysis of an extracytoplasmic-function sigma factor to investigate its interactions with RNA polymerase and DNA.||Journal of bacteriology||2006||M. Wilson, I. Lamont||PubMed: 16484205||ECF43|
|The third pillar of bacterial signal transduction: classification of the extracytoplasmic function (ECF) sigma factor protein family.||Molecular microbiology||2009||A. Staroń, H. Sofia, S. Dietrich, L. Ulrich, H. Liesegang, T. Mascher||PubMed: 19737356||ECF103, ECF21, ECF123, ECF51, ECF39, ECF281, ECF102, ECF130, ECF122, ECF291, ECF15, ECF242, ECF22, ECF285, ECF106, ECF27, ECF31, ECF240, ECF114, ECF16, ECF38, ECF41, ECF105, ECF116, ECF111, ECF03, ECF239, ECF42, ECF294, ECF17, ECF11, ECF29, ECF235, ECF293, ECF118, ECF265, ECF30, ECF23, ECF14, ECF249, ECF18, ECF115, ECF290, ECF25, ECF121, ECF02, ECF120, ECF289, ECF28, ECF243, ECF19, ECF43, ECF107, ECF12, ECF32, ECF36, ECF292, ECF286, ECF271, ECF26, ECF40, ECF56, ECF33|