Protein-glutamate methylesterase

Protein-glutamate methylesterase
protein-glutamate methylesterase
Identifiers
EC number 3.1.1.61
CAS number 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 / EGO
CheB_methylest
PDB 1a2o EBI.jpg
structural basis for methylesterase cheb regulation by a phosphorylation-activated domain
Identifiers
Symbol CheB_methylest
Pfam PF01339
InterPro IPR000673
SCOP 1chd

In enzymology, a protein-glutamate methylesterase (EC 3.1.1.61) is an enzyme that catalyzes the chemical reaction

protein L-glutamate O5-methyl ester + H2O \rightleftharpoons protein L-glutamate + methanol

Thus, the two substrates of this enzyme are protein L-glutamate O5-methyl ester and H2O, whereas its two products are protein L-glutamate and 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 of this enzyme class is protein-L-glutamate-O5-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 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, 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

As of late 2007, two structures have been solved for this class of enzymes, with PDB accession codes 1A2O and 1CHD.


References

  1. ^ 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. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1233412. 
  2. ^ 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

  • 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. PMID 6384215. 

This article includes text from the public domain Pfam and InterPro IPR000673


Stub icon This hydrolase article is a stub. You can help Wikipedia by expanding it.