Protein-glutamate methylesterase
| protein-glutamate methylesterase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 3.1.1.61 | ||||||||
| CAS no. | 93792-01-9 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| Gene Ontology | AmiGO / QuickGO | ||||||||
| |||||||||
| CheB_methylest | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 structural basis for methylesterase cheb regulation by a phosphorylation-activated domain | |||||||||
| Identifiers | |||||||||
| Symbol | CheB_methylest | ||||||||
| Pfam | PF01339 | ||||||||
| InterPro | IPR000673 | ||||||||
| SCOP2 | 1chd / SCOPe / SUPFAM | ||||||||
| |||||||||
The enzyme protein-glutamate methylesterase (EC 3.1.1.61) catalyzes the reaction
- protein L-glutamate O 5-methyl ester + H2O protein L-glutamate + methanol
This enzyme is a demethylase, and more specifically it belongs to the family of hydrolases, specifically those acting on carboxylic ester bonds. The systematic name is protein-Lglutamate-O 5-methyl-ester acylhydrolase. Other names in common use include chemotaxis-specific methylesterase, methyl-accepting chemotaxis protein methyl-esterase, CheB methylesterase, methylesterase CheB, protein methyl-esterase, protein carboxyl methylesterase, PME, protein methylesterase, and protein-L-glutamate-5-O-methyl-ester acylhydrolase. This enzyme participates in 3 metabolic pathways: two-component system - general, bacterial chemotaxis - general, and bacterial chemotaxis - organism-specific.
CheB is part of a two-component signal transduction system. These systems enable bacteria to sense, respond, and adapt to a wide range of environments, stressors, and growth conditions.[1] Two-component systems are composed of a sensor histidine kinase (HK) and its cognate response regulator (RR).[2] The HK catalyses its own autophosphorylation followed by the transfer of the phosphoryl group to the receiver domain on RR; phosphorylation of the RR usually activates an attached output domain, in this case a methyltransferase domain.
CheB is 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). 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.
Structural studies
[edit]As of late 2007, two structures have been solved for this class of enzymes, with PDB accession codes 1A2O and 1CHD.
References
[edit]- ^ Skerker JM, Prasol MS, Perchuk BS, Biondi EG, Laub MT (October 2005). "Two-component signal transduction pathways regulating growth and cell cycle progression in a bacterium: a system-level analysis". PLOS Biol. 3 (10): e334. doi:10.1371/journal.pbio.0030334. PMC 1233412. PMID 16176121.
- ^ Stock AM, Robinson VL, Goudreau PN (2000). "Two-component signal transduction". Annu. Rev. Biochem. 69: 183–215. doi:10.1146/annurev.biochem.69.1.183. PMID 10966457.
Further reading
[edit]- Kehry MR, Doak TG, Dahlquist FW (1984). "Stimulus-induced changes in methylesterase activity during chemotaxis in Escherichia coli". J. Biol. Chem. 259 (19): 11828–35. doi:10.1016/S0021-9258(20)71286-X. PMID 6384215.
