Summary: CheB methylesterase

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Wikipedia: Protein-glutamate methylesterase
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This is the Wikipedia entry entitled "Protein-glutamate methylesterase". More...

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Protein-glutamate methylesterase

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protein-glutamate methylesterase

Identifiers

Databases

PDB structures

AmiGO / EGO

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PMC	articles
PubMed	articles

CheB_methylest

structural basis for methylesterase cheb regulation by a phosphorylation-activated domain

Identifiers

Symbol

CheB_methylest

Available protein structures:
Pfam	structures
PDB	RCSB PDB; PDBe
PDBsum	structure summary

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 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.

[edit] Structural studies

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

[edit] References

^ 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.
^ 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.

[edit] 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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CheB methylesterase

No Pfam abstract.

Literature references

West AH, Martinez-Hackert E, Stock AM; , J Mol Biol 1995;250:276-290.: Crystal structure of the catalytic domain of the chemotaxis receptor methylesterase, CheB. PUBMED:7608974

External database links

PANDIT:	PF01339
Pseudofam:	PF01339
SCOP:	1chd
SYSTERS:	CheB_methylest

This tab holds annotation information from the InterPro database.

InterPro entry IPR000673

Two-component signal transduction systems enable bacteria to sense, respond, and adapt to a wide range of environments, stressors, and growth conditions [PUBMED:16176121]. Some bacteria can contain up to as many as 200 two-component systems that need tight regulation to prevent unwanted cross-talk [PUBMED: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 [PUBMED:12372152]. Two-component systems are comprised of a sensor histidine kinase (HK) and its cognate response regulator (RR) [PUBMED: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 [PUBMED:11934609, PUBMED: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.

Gene Ontology

The mapping between Pfam and Gene Ontology is provided by InterPro. If you use this data please cite InterPro.

Cellular component	cytoplasm (GO:0005737)
Molecular function	two-component response regulator activity (GO:0000156)
Molecular function	protein-glutamate methylesterase activity (GO:0008984)
Biological process	two-component signal transduction system (phosphorelay) (GO:0000160)
Biological process	chemotaxis (GO:0006935)

Domain organisation

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Alignments

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Alignment:	Seed (180) Full (2433) NCBI (2271) Metagenomics (363)
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Alignment:	Seed (180) Full (2433)
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The main seed and full alignments are generated using sequences from the UniProt sequence database. However, we also generate alignments using sequences from the NCBI sequence database and the "metaseq" metagenomics dataset.

You can view alignments from these two additional datasets using the form above, or you can download alignments of NCBI or metagenomics sequences, as gzip-compressed files.

Pfam alignments:	Seed (180) Full (2433) NCBI (2271) Metagenomics (363)
Full length sequences	Full-sequences (2433)

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Curation and family details

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Curation

Seed source:

Sarah Teichmann

Previous IDs:

none

Type:

Domain

Author:

Finn RD, Bateman A

Number in seed:

180

Number in full:

2433

Average length of the domain:

180.80 aa

Average identity of full alignment:

37 %

Average coverage of the sequence by the domain:

40.95 %

HMM information

HMM build commands:

build method: hmmbuild -o /dev/null HMM SEED

search method: hmmsearch -Z 15929002 -E 1000 --cpu 4 HMM pfamseq

Model details:

Parameter	Sequence	Domain
Gathering cut-off	20.4	20.4
Trusted cut-off	24.3	24.3
Noise cut-off	20.0	18.8

Model length:

182

Family (HMM) version:

12

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Species distribution

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Archea	Eukaryota
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Interactions

There are 2 interactions for this family. More...

Response_reg CheB_methylest

Family: CheB_methylest (PF01339)

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Summary: CheB methylesterase

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Protein-glutamate methylesterase

[edit] Structural studies

[edit] References

[edit] Further reading

CheB methylesterase

Literature references

External database links

InterPro entry IPR000673

Gene Ontology

Domain organisation

Alignments

Viewing

Downloading

View options

Formatting options

Download options

External links

HMM logo

Trees

Curation and family details

Curation

HMM information

Species distribution

Sunburst controls

Weight segments by...

Change the size of the sunburst

Colour assignments

How the sunburst is generated

Colouring and labels

Anomalies in the taxonomy tree

Missing taxonomic levels

Unmapped species names

Sub-species

Too many species/sequences

Tree controls

Annotation

Download tree

Selected sequences

Species trees

Interactive tree

Interactions