Conserved Site

Sigma-54 interaction domain, conserved site (IPR025944)

Short name: Sigma_54_int_dom_CS


Some bacterial regulatory proteins activate the expression of genes from promoters recognised by core RNA polymerase associated with the alternative sigma-54 factor. These have a conserved domain of about 230 residues involved in the ATP-dependent [PMID: 8407777, PMID: 2041769] interaction with sigma-54. About half of the proteins in which this domain is found (algB, dcdT, flbD, hoxA, hupR1, hydG, ntrC, pgtA and pilR) belong to signal transduction two-component systems [PMID: 2694934] and possess a domain that can be phosphorylated by a sensor-kinase protein in their N-terminal section. Almost all of these proteins possess a helix-turn-helix DNA-binding domain in their C-terminal section.

The domain involved in interaction with the sigma-54 factor has an ATPase activity. This may be required to promote a conformational change necessary for the interaction [PMID: 1534752]. The domain contains an atypical ATP-binding motif A (P-loop) as well as a form of motif B.

This entry represents a conserved site found in the C-terminal section of the sigma-54 interaction domain.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE patterns