Q838D6 · TYRDC_ENTFA
- ProteinL-tyrosine decarboxylase
- Genetdc
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids620 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Catalyzes the decarboxylation of L-tyrosine to produce tyramine (PubMed:30659181).
Plays a role in acid resistance since tyramine production via tyrosine decarboxylation appears to provide a cytosolic pH maintenance mechanism that helps the bacterium cope with acid stress such as that encountered in gastrointestinal tract (GIT) environments. Therefore, may contribute to the colonization of the human GIT by E.faecalis (PubMed:25529314).
Plays a role in acid resistance since tyramine production via tyrosine decarboxylation appears to provide a cytosolic pH maintenance mechanism that helps the bacterium cope with acid stress such as that encountered in gastrointestinal tract (GIT) environments. Therefore, may contribute to the colonization of the human GIT by E.faecalis (PubMed:25529314).
Also involved in drug metabolism, being able to catalyze decarboxylation of levodopa (L-dopa) to dopamine. In gut microbiota this enzyme is in fact exclusively responsible for the decarboxylation of levodopa, and thus reduces in situ levels of levodopa in the treatment of Parkinson's disease. It was shown that abundance of bacterial tyrosine decarboxylase in the proximal small intestine - the primary site of levodopa absorption - contributes to interindividual variation in drug efficacy and can explain the requirement for an increased dosage regimen of levodopa treatment in Parkinson's disease patients.
Catalytic activity
- L-tyrosine + H+ = tyramine + CO2This reaction proceeds in the forward direction.
- L-dopa + H+ = dopamine + CO2This reaction proceeds in the forward direction.
Cofactor
Activity regulation
Levodopa decarboxylation is not inhibited by carbidopa, benserazide, and methyldopa, that are three human L-dopa decarboxylase inhibitors.
Kinetics
KM | SUBSTRATE | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|---|
0.6 mM | L-tyrosine | 5.0 | ||||
3 mM | L-dopa | 5.0 |
Vmax | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|
69.6 μmol/min/mg | 5.0 | for the decarboxylation of L-tyrosine | |||
35.3 μmol/min/mg | 5.0 | for the decarboxylation of L-dopa |
kcat is 6963 min-1 for the decarboxylation of L-tyrosine. kcat is 3531 min-1 for the decarboxylation of L-dopa (at pH 5.0).
Pathway
Amino-acid metabolism.
Features
Showing features for binding site, active site.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Binding site | 158-159 | pyridoxal 5'-phosphate (UniProtKB | ChEBI); ligand shared between dimeric partners; in other chain | |||
Binding site | 298 | pyridoxal 5'-phosphate (UniProtKB | ChEBI); ligand shared between dimeric partners; in other chain | |||
Binding site | 389-391 | pyridoxal 5'-phosphate (UniProtKB | ChEBI); ligand shared between dimeric partners; in other chain | |||
Active site | 420 | Proton donor | |||
Binding site | 440 | pyridoxal 5'-phosphate (UniProtKB | ChEBI); ligand shared between dimeric partners | |||
GO annotations
Aspect | Term | |
---|---|---|
Molecular Function | L-dopa decarboxylase activity | |
Molecular Function | pyridoxal phosphate binding | |
Molecular Function | tyrosine decarboxylase activity | |
Biological Process | L-dopa metabolic process |
Keywords
- Molecular function
- Biological process
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameL-tyrosine decarboxylase
- EC number
- Short namesTDC
- Alternative names
Gene names
Organism names
- Strain
- Taxonomic lineageBacteria > Bacillota > Bacilli > Lactobacillales > Enterococcaceae > Enterococcus
Accessions
- Primary accessionQ838D6
Proteomes
Phenotypes & Variants
Disruption phenotype
Cells lacking the tdc cluster (tyrS, tdc/tdcA, tyrP and nhaC-2) lose the ability to produce tyramine, and show reduced viability under acidic pHs in the presence of tyrosine.
PTM/Processing
Features
Showing features for chain, modified residue.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Chain | PRO_0000448496 | 1-620 | L-tyrosine decarboxylase | ||
Modified residue | 392 | N6-(pyridoxal phosphate)lysine | |||
Expression
Induction
Up-regulated by tyrosine and acidic pH. Makes part of an operon together with tyrP and nhaC-2.
Interaction
Structure
Sequence
- Sequence statusComplete
- Length620
- Mass (Da)70,053
- Last updated2019-11-13 v2
- ChecksumA83C598048C7D5E1
Sequence caution
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
AE016830 EMBL· GenBank· DDBJ | AAO80459.1 EMBL· GenBank· DDBJ | Genomic DNA | Different initiation |