P18956 · GGT_ECOLI

Function

function

Cleaves the gamma-glutamyl bond of periplasmic glutathione (gamma-Glu-Cys-Gly), glutathione conjugates, and other gamma-glutamyl compounds. The metabolism of glutathione releases free glutamate and the dipeptide cysteinyl-glycine, which is hydrolyzed to cysteine and glycine by dipeptidases; it may function in amino acid uptake/salvage, or possibly in peptidoglycan linkage. Catalyzes the hydrolysis and transpeptidation of many gamma-glutamyl compounds (including some D-gamma-glutamyl substrates), with a preference for basic and aromatic amino acids as acceptors (PubMed:2877974).
The KM values for gamma-glutamyl acceptors are so high that it has been proposed transpeptidation is not the physiological role in E.coli (PubMed:2877974, PubMed:8104180).

Catalytic activity

Activity regulation

Transferase and hydrolase activities are inhibited by L-Ala and L-Gln, and also by GGT affinity labeling reagents such as azaserine and 6-diazo-5-oxo-nor-leucine.

Kinetics

KM SUBSTRATE pH TEMPERATURE[C] NOTES EVIDENCE
35 μMglutathione transfer to glycylglycine (gly-gly)
35 μMgamma-glutamyl-p-nitroanilide (gamma-GpNA)
29 μMglutathione hydrolysis
68 μMgamma-GpNA hydrolysis

pH Dependence

Optimum pH is 8.73 for transfer of p-nitroanilide from gamma-GpNA to gly-gly and 9.25 for hydrolysis of gamma-GpNA.

Temperature Dependence

Optimum temperature is 50 degrees Celsius for both transferase and hydrolase activities.

Pathway

Sulfur metabolism; glutathione metabolism.

Features

Showing features for binding site, active site.

TypeIDPosition(s)Description
Binding site114L-glutamate (UniProtKB | ChEBI)
Active site391Nucleophile
Binding site409L-glutamate (UniProtKB | ChEBI)
Binding site411L-glutamate (UniProtKB | ChEBI)
Binding site430L-glutamate (UniProtKB | ChEBI)
Binding site433L-glutamate (UniProtKB | ChEBI)
Binding site462-463L-glutamate (UniProtKB | ChEBI)
Binding site483-484L-glutamate (UniProtKB | ChEBI)

GO annotations

AspectTerm
Cellular Componentouter membrane-bounded periplasmic space
Cellular Componentperiplasmic space
Molecular Functiongamma-glutamyl-peptidase activity
Molecular Functionglutathione hydrolase activity
Molecular Functionleukotriene C4 gamma-glutamyl transferase activity
Biological Processamino acid salvage
Biological Processglutathione biosynthetic process
Biological Processglutathione catabolic process
Biological Processself proteolysis

Keywords

Enzyme and pathway databases

Protein family/group databases

Names & Taxonomy

Protein names

Gene names

    • Name
      ggt
    • Ordered locus names
      b3447, JW3412

Organism names

  • Taxonomic identifier
  • Strains
    • K12
    • K12 / MG1655 / ATCC 47076
    • K12 / W3110 / ATCC 27325 / DSM 5911
  • Taxonomic lineage
    Bacteria > Pseudomonadota > Gammaproteobacteria > Enterobacterales > Enterobacteriaceae > Escherichia

Accessions

  • Primary accession
    P18956
  • Secondary accessions
    • Q2M7B0

Proteomes

Subcellular Location

Keywords

Phenotypes & Variants

Disruption phenotype

Loss of growth using exogenous gamma-glutamyl peptides as amino acid sources.

Features

Showing features for mutagenesis.

TypeIDPosition(s)Description
Mutagenesis391Abolishes autocatalytic cleavage, loss of enzymatic activity.
Mutagenesis513Not processed into its subunits, loss of enzymatic activity.
Mutagenesis571Not processed into its subunits, loss of enzymatic activity.

PTM/Processing

Features

Showing features for signal, chain.

TypeIDPosition(s)Description
Signal1-25
ChainPRO_000001105226-390Glutathione hydrolase large chain
ChainPRO_0000011053391-580Glutathione hydrolase small chain

Post-translational modification

Cleaved by autocatalysis into a large and a small subunit.

Keywords

Proteomic databases

Interaction

Subunit

This enzyme consists of two polypeptide chains, which are synthesized in precursor form from a single polypeptide.

Protein-protein interaction databases

Family & Domains

Features

Showing features for region.

TypeIDPosition(s)Description
Region561-580Disordered

Sequence similarities

Belongs to the gamma-glutamyltransferase family.

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Sequence processing
    The displayed sequence is further processed into a mature form.
  • Length
    580
  • Mass (Da)
    61,768
  • Last updated
    1990-11-01 v1
  • Checksum
    772F652EBA2A5F00
MIKPTFLRRVAIAALLSGSCFSAAAAPPAPPVSYGVEEDVFHPVRAKQGMVASVDATATQVGVDILKEGGNAVDAAVAVGYALAVTHPQAGNLGGGGFMLIRSKNGNTTAIDFREMAPAKATRDMFLDDQGNPDSKKSLTSHLASGTPGTVAGFSLALDKYGTMPLNKVVQPAFKLARDGFIVNDALADDLKTYGSEVLPNHENSKAIFWKEGEPLKKGDTLVQANLAKSLEMIAENGPDEFYKGTIAEQIAQEMQKNGGLITKEDLAAYKAVERTPISGDYRGYQVYSMPPPSSGGIHIVQILNILENFDMKKYGFGSADAMQIMAEAEKYAYADRSEYLGDPDFVKVPWQALTNKAYAKSIADQIDINKAKPSSEIRPGKLAPYESNQTTHYSVVDKDGNAVAVTYTLNTTFGTGIVAGESGILLNNQMDDFSAKPGVPNVYGLVGGDANAVGPNKRPLSSMSPTIVVKDGKTWLVTGSPGGSRIITTVLQMVVNSIDYGLNVAEATNAPRFHHQWLPDELRVEKGFSPDTLKLLEAKGQKVALKEAMGSTQSIMVGPDGELYGASDPRSVDDLTAGY

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
M28722
EMBL· GenBank· DDBJ
AAA23869.1
EMBL· GenBank· DDBJ
Genomic DNA
U18997
EMBL· GenBank· DDBJ
AAA58245.1
EMBL· GenBank· DDBJ
Genomic DNA
U00096
EMBL· GenBank· DDBJ
AAC76472.1
EMBL· GenBank· DDBJ
Genomic DNA
AP009048
EMBL· GenBank· DDBJ
BAE77846.1
EMBL· GenBank· DDBJ
Genomic DNA
U00039
EMBL· GenBank· DDBJ
AAB18422.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

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