Domain

Signal transduction response regulator, chemotaxis, protein-glutamate methylesterase (IPR000673)

Short name: Sig_transdc_resp-reg_Me-estase

Domain relationships

None.

Description

Two-component signal transduction systems enable bacteria to sense, respond, and adapt to a wide range of environments, stressors, and growth conditions [PMID: 16176121]. Some bacteria can contain up to as many as 200 two-component systems that need tight regulation to prevent unwanted cross-talk [PMID: 18076326]. These pathways have been adapted to response to a wide variety of stimuli, including nutrients, cellular redox state, changes in osmolarity, quorum signals, antibiotics, and more [PMID: 12372152]. Two-component systems are comprised of a sensor histidine kinase (HK) and its cognate response regulator (RR) [PMID: 10966457]. The HK catalyses its own auto-phosphorylation followed by the transfer of the phosphoryl group to the receiver domain on RR; phosphorylation of the RR usually activates an attached output domain, which can then effect changes in cellular physiology, often by regulating gene expression. Some HK are bifunctional, catalysing both the phosphorylation and dephosphorylation of their cognate RR. The input stimuli can regulate either the kinase or phosphatase activity of the bifunctional HK.

A variant of the two-component system is the phospho-relay system. Here a hybrid HK auto-phosphorylates and then transfers the phosphoryl group to an internal receiver domain, rather than to a separate RR protein. The phosphoryl group is then shuttled to histidine phosphotransferase (HPT) and subsequently to a terminal RR, which can evoke the desired response [PMID: 11934609, PMID: 11489844].

This entry represents the signal transduction response regulator CheB involved in chemotaxis. CheB methylesterase is responsible for removing the methyl group from the gamma-glutamyl methyl ester residues in the methyl-accepting chemotaxis proteins (MCP). The enzyme catalyses the reaction: protein L-glutamate O-methyl ester and water is converted to protein L-glutamate and methanol. CheB is regulated through phosphorylation by CheA. The N-terminal region of the protein is similar to that of other regulatory components of sensory transduction systems. The Myxococcus xanthus FrzG protein also belongs to this family, and is required for the normal aggregation of cells during fruiting body formation.

GO terms

Biological Process

GO:0006935 chemotaxis
GO:0000160 phosphorelay signal transduction system

Molecular Function

GO:0000156 phosphorelay response regulator activity
GO:0008984 protein-glutamate methylesterase activity

Cellular Component

GO:0005737 cytoplasm

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
SUPERFAMILY
PROSITE profiles
Pfam
GENE3D