P11954 · TDCB_SALTY
- ProteinL-threonine dehydratase catabolic TdcB
- GenetdcB
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids329 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Catalyzes the anaerobic formation of alpha-ketobutyrate and ammonia from threonine in a two-step reaction. The first step involved a dehydration of threonine and a production of enamine intermediates (aminocrotonate), which tautomerizes to its imine form (iminobutyrate). Both intermediates are unstable and short-lived. The second step is the nonenzymatic hydrolysis of the enamine/imine intermediates to form 2-ketobutyrate and free ammonia. In the low water environment of the cell, the second step is accelerated by RidA. TdcB also dehydrates serine to yield pyruvate via analogous enamine/imine intermediates.
Catalytic activity
- L-threonine = 2-oxobutanoate + NH4+
Cofactor
Activity regulation
Each protein molecule can bind up to four molecules of AMP, which act as an allosteric activator to the enzyme. The enzyme is inhibited by alpha-keto acids and other catabolites.
Kinetics
KM | SUBSTRATE | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|---|
16 mM | L-threonine | 8 | in the presence of 5 mM of AMP 25 dregrees Celsius | |||
32 mM | L-threonine | 8 | in the presence of 5 mM of CMP 25 dregrees Celsius | |||
123 mM | L-threonine | 8 | 25 dregrees Celsius |
Pathway
Amino-acid degradation; L-threonine degradation via propanoate pathway; propanoate from L-threonine: step 1/4.
Features
Showing features for binding site.
GO annotations
Aspect | Term | |
---|---|---|
Molecular Function | L-serine ammonia-lyase activity | |
Molecular Function | nucleotide binding | |
Molecular Function | pyridoxal phosphate binding | |
Molecular Function | threonine deaminase activity | |
Biological Process | isoleucine biosynthetic process | |
Biological Process | L-serine catabolic process | |
Biological Process | L-threonine catabolic process to propionate | |
Biological Process | threonine catabolic process |
Keywords
- Molecular function
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameL-threonine dehydratase catabolic TdcB
- EC number
- Alternative names
Gene names
Organism names
- Strain
- Taxonomic lineageBacteria > Pseudomonadota > Gammaproteobacteria > Enterobacterales > Enterobacteriaceae > Salmonella
Accessions
- Primary accessionP11954
Proteomes
PTM/Processing
Features
Showing features for chain, modified residue.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000185585 | 1-329 | L-threonine dehydratase catabolic TdcB | |||
Sequence: MHITYDLPVAIEDILEAKKRLAGKIYKTGMPRSNYFSERCKGEIFLKFENMQRTGSFKIRGAFNKLSSLTEAEKRKGVVACSAGNHAQGVSLSCAMLGIDGKVVMPKGAPKSKVAATCDYSAEVVLHGDNFNDTIAKVSEIVETEGRIFIPPYDDPKVIAGQGTIGLEIMEDLYDVDNVIVPIGGGGLIAGIAIAIKSINPTIKVIGVQAENVHGMAASYYTGEITTHRTTGTLADGCDVSRPGNLTYEIVRELVDDIVLVSEDEIRNSMIALIQRNKVITEGAGALACAALLSGKLDSHIQNRKTVSIISGGNIDLSRVSQITGLVDA | ||||||
Modified residue | 58 | N6-(pyridoxal phosphate)lysine | ||||
Sequence: K |
Proteomic databases
Interaction
Subunit
In the native structure, TdcB is in a dimeric form, whereas in the TdcB-AMP complex, it exists in a tetrameric form (dimer of dimers).
Protein-protein interaction databases
Structure
Sequence
- Sequence statusComplete
- Length329
- Mass (Da)35,141
- Last updated2001-12-13 v2
- ChecksumC1C619B021DE817C
Features
Showing features for sequence conflict.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Sequence conflict | 24 | in Ref. 2; AA sequence | ||||
Sequence: K → I |
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
AE006468 EMBL· GenBank· DDBJ | AAL22117.1 EMBL· GenBank· DDBJ | Genomic DNA |