Protein-glutamate methylesterase

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protein-glutamate methylesterase
Identifiers
EC no.3.1.1.61
CAS no.93792-01-9
Databases
IntEnzIntEnz view
BRENDABRENDA entry
ExPASyNiceZyme view
KEGGKEGG entry
MetaCycmetabolic pathway
PRIAMprofile
PDB structuresRCSB PDB PDBe PDBsum
Gene OntologyAmiGO / QuickGO
CheB_methylest
1a2o structure.png
structural basis for methylesterase cheb regulation by a phosphorylation-activated domain
Identifiers
SymbolCheB_methylest
PfamPF01339
InterProIPR000673
SCOP21chd / SCOPe / SUPFAM

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 protein L-glutamate + methanol

Thus, the two substrates of this enzyme are and H2O, whereas its two products are 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 .

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 . 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.
  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 incorporates text from the public domain Pfam and InterPro: IPR000673


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