Q838D6 · TYRDC_ENTFA

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).
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

Cofactor

pyridoxal 5'-phosphate (UniProtKB | Rhea| CHEBI:597326 )

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 mML-tyrosine5.0
3 mML-dopa5.0
Vmax pH TEMPERATURE[C] NOTES EVIDENCE
69.6 μmol/min/mg5.0for the decarboxylation of L-tyrosine
35.3 μmol/min/mg5.0for 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
IDPosition(s)Description
Binding site158-159pyridoxal 5'-phosphate (UniProtKB | ChEBI); ligand shared between dimeric partners; in other chain
Binding site298pyridoxal 5'-phosphate (UniProtKB | ChEBI); ligand shared between dimeric partners; in other chain
Binding site389-391pyridoxal 5'-phosphate (UniProtKB | ChEBI); ligand shared between dimeric partners; in other chain
Active site420Proton donor
Binding site440pyridoxal 5'-phosphate (UniProtKB | ChEBI); ligand shared between dimeric partners

GO annotations

AspectTerm
Molecular FunctionL-dopa decarboxylase activity
Molecular Functionpyridoxal phosphate binding
Molecular Functiontyrosine decarboxylase activity
Biological ProcessL-dopa metabolic process

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    L-tyrosine decarboxylase
  • EC number
  • Short names
    TDC
  • Alternative names
    • Levodopa decarboxylase
      (L-dopa decarboxylase
      ) (EC:4.1.1.-
      ) . EC:4.1.1.- (UniProtKB | ENZYME | Rhea)

Gene names

    • Name
      tdc
    • Synonyms
      tdcA
    • Ordered locus names
      EF_0634

Organism names

Accessions

  • Primary accession
    Q838D6

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
IDPosition(s)Description
ChainPRO_00004484961-620L-tyrosine decarboxylase
Modified residue392N6-(pyridoxal phosphate)lysine

Expression

Induction

Up-regulated by tyrosine and acidic pH. Makes part of an operon together with tyrP and nhaC-2.

Interaction

Subunit

Homodimer.

Protein-protein interaction databases

Family & Domains

Sequence similarities

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    620
  • Mass (Da)
    70,053
  • Last updated
    2019-11-13 v2
  • Checksum
    A83C598048C7D5E1
MKNEKLAKGEMNLNALFIGDKAENGQLYKDLLIDLVDEHLGWRQNYMPQDMPVISSQERTSESYEKTVNHMKDVLNEISSRMRTHSVPWHTAGRYWGHMNSETLMPSLLAYNFAMLWNGNNVAYESSPATSQMEEEVGHEFAHLMSYKNGWGHIVADGSLANLEGLWYARNIKSLPFAMKEVKPELVAGKSDWELLNMPTKEIMDLLESAEDEIDEIKAHSARSGKHLQAIGKWLVPQTKHYSWLKAADIIGIGLDQVIPVPVDHNYRMDINELEKIVRGLAEEQIPVLGVVGVVGSTEEGAVDSIDKIIALRDELMKDGIYYYVHVDAAYGGYGRAIFLDEDNNFIPYEDLQDVHEEYGVFKEKKEHISREVYDAYKAIELAESVTIDPHKMGYIPYSAGGIVIQDIRMRDVISYFATYVFEKGADIPALLGAYILEGSKAGATAASVWAAHHVLPLNVAGYGKLIGASIEGSHHFYNFLNDLTFKVGDKEIEVHTLTHPDFNMVDYVFKEKGNDDLVAMNKLNHDVYDYASYVKGNIYNNEFITSHTDFAIPDYGNSPLKFVNSLGFSDEEWNRAGKVTVLRAAVMTPYMNDKEEFDVYAPKIQAALQEKLEQIYDVK

Sequence caution

The sequence AAO80459.1 differs from that shown. Reason: Erroneous initiation Truncated N-terminus.

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
AE016830
EMBL· GenBank· DDBJ
AAO80459.1
EMBL· GenBank· DDBJ
Genomic DNA Different initiation

Genome annotation databases

Similar Proteins

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