ID   TDCB_ECOL6              Reviewed;         329 AA.
AC   P0AGF7; P05792;
DT   20-DEC-2005, integrated into UniProtKB/Swiss-Prot.
DT   20-DEC-2005, sequence version 1.
DT   03-AUG-2022, entry version 85.
DE   RecName: Full=L-threonine dehydratase catabolic TdcB;
DE            EC=4.3.1.19;
DE   AltName: Full=L-serine dehydratase;
DE            EC=4.3.1.17;
DE   AltName: Full=Threonine deaminase;
GN   Name=tdcB; OrderedLocusNames=c3875;
OS   Escherichia coli O6:H1 (strain CFT073 / ATCC 700928 / UPEC).
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC   Enterobacteriaceae; Escherichia.
OX   NCBI_TaxID=199310;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=CFT073 / ATCC 700928 / UPEC;
RX   PubMed=12471157; DOI=10.1073/pnas.252529799;
RA   Welch R.A., Burland V., Plunkett G. III, Redford P., Roesch P., Rasko D.,
RA   Buckles E.L., Liou S.-R., Boutin A., Hackett J., Stroud D., Mayhew G.F.,
RA   Rose D.J., Zhou S., Schwartz D.C., Perna N.T., Mobley H.L.T.,
RA   Donnenberg M.S., Blattner F.R.;
RT   "Extensive mosaic structure revealed by the complete genome sequence of
RT   uropathogenic Escherichia coli.";
RL   Proc. Natl. Acad. Sci. U.S.A. 99:17020-17024(2002).
CC   -!- FUNCTION: Catalyzes the anaerobic formation of alpha-ketobutyrate and
CC       ammonia from threonine in a two-step reaction. The first step involved
CC       a dehydration of threonine and a production of enamine intermediates
CC       (aminocrotonate), which tautomerizes to its imine form (iminobutyrate).
CC       Both intermediates are unstable and short-lived. The second step is the
CC       nonenzymatic hydrolysis of the enamine/imine intermediates to form 2-
CC       ketobutyrate and free ammonia. In the low water environment of the
CC       cell, the second step is accelerated by RidA. TdcB also dehydrates
CC       serine to yield pyruvate via analogous enamine/imine intermediates (By
CC       similarity). {ECO:0000250}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=L-threonine = 2-oxobutanoate + NH4(+); Xref=Rhea:RHEA:22108,
CC         ChEBI:CHEBI:16763, ChEBI:CHEBI:28938, ChEBI:CHEBI:57926; EC=4.3.1.19;
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=L-serine = NH4(+) + pyruvate; Xref=Rhea:RHEA:19169,
CC         ChEBI:CHEBI:15361, ChEBI:CHEBI:28938, ChEBI:CHEBI:33384; EC=4.3.1.17;
CC   -!- COFACTOR:
CC       Name=pyridoxal 5'-phosphate; Xref=ChEBI:CHEBI:597326;
CC         Evidence={ECO:0000250};
CC   -!- ACTIVITY REGULATION: Each protein molecule can bind up to four
CC       molecules of AMP, which act as an allosteric activator to the enzyme.
CC       {ECO:0000250}.
CC   -!- PATHWAY: Amino-acid degradation; L-threonine degradation via propanoate
CC       pathway; propanoate from L-threonine: step 1/4.
CC   -!- SUBUNIT: In the native structure, TdcB is in a dimeric form, whereas in
CC       the TdcB-AMP complex, it exists in a tetrameric form (dimer of dimers).
CC       {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the serine/threonine dehydratase family.
CC       {ECO:0000305}.
CC   ---------------------------------------------------------------------------
CC   Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC   Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC   ---------------------------------------------------------------------------
DR   EMBL; AE014075; AAN82316.1; -; Genomic_DNA.
DR   RefSeq; WP_000548347.1; NC_004431.1.
DR   AlphaFoldDB; P0AGF7; -.
DR   SMR; P0AGF7; -.
DR   STRING; 199310.c3875; -.
DR   EnsemblBacteria; AAN82316; AAN82316; c3875.
DR   GeneID; 66672982; -.
DR   KEGG; ecc:c3875; -.
DR   eggNOG; COG1171; Bacteria.
DR   HOGENOM; CLU_021152_4_2_6; -.
DR   OMA; LIHPFDH; -.
DR   BioCyc; ECOL199310:C3875-MON; -.
DR   UniPathway; UPA00052; UER00507.
DR   Proteomes; UP000001410; Chromosome.
DR   GO; GO:0003941; F:L-serine ammonia-lyase activity; IEA:UniProtKB-EC.
DR   GO; GO:0004794; F:L-threonine ammonia-lyase activity; IEA:UniProtKB-EC.
DR   GO; GO:0000166; F:nucleotide binding; IEA:UniProtKB-KW.
DR   GO; GO:0030170; F:pyridoxal phosphate binding; IEA:InterPro.
DR   GO; GO:0070689; P:L-threonine catabolic process to propionate; IEA:UniProtKB-UniPathway.
DR   Gene3D; 3.40.50.1100; -; 2.
DR   InterPro; IPR001926; PLP-dep.
DR   InterPro; IPR000634; Ser/Thr_deHydtase_PyrdxlP-BS.
DR   InterPro; IPR005789; Thr_deHydtase_catblc.
DR   InterPro; IPR036052; Trypto_synt_PLP_dependent.
DR   Pfam; PF00291; PALP; 1.
DR   SUPFAM; SSF53686; SSF53686; 1.
DR   TIGRFAMs; TIGR01127; ilvA_1Cterm; 1.
DR   PROSITE; PS00165; DEHYDRATASE_SER_THR; 1.
PE   3: Inferred from homology;
KW   Allosteric enzyme; Lyase; Nucleotide-binding; Pyridoxal phosphate.
FT   CHAIN           1..329
FT                   /note="L-threonine dehydratase catabolic TdcB"
FT                   /id="PRO_0000185584"
FT   BINDING         53..54
FT                   /ligand="AMP"
FT                   /ligand_id="ChEBI:CHEBI:456215"
FT                   /evidence="ECO:0000250"
FT   BINDING         88
FT                   /ligand="AMP"
FT                   /ligand_id="ChEBI:CHEBI:456215"
FT                   /evidence="ECO:0000250"
FT   BINDING         119..120
FT                   /ligand="AMP"
FT                   /ligand_id="ChEBI:CHEBI:456215"
FT                   /evidence="ECO:0000250"
FT   BINDING         314
FT                   /ligand="AMP"
FT                   /ligand_id="ChEBI:CHEBI:456215"
FT                   /evidence="ECO:0000250"
FT   MOD_RES         58
FT                   /note="N6-(pyridoxal phosphate)lysine"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   329 AA;  35232 MW;  E7DF018FCCF743B1 CRC64;
     MHITYDLPVA IDDIIEAKQR LAGRIYKTGM PRSNYFSERC KGEIFLKFEN MQRTGSFKIR
     GAFNKLSSLT DAEKRKGVVA CSAGNHAQGV SLSCAMLGID GKVVMPKGAP KSKVAATCDY
     SAEVVLHGDN FNDTIAKVSE IVEMEGRIFI PPYDDPKVIA GQGTIGLEIM EDLYDVDNVI
     VPIGGGGLIA GIAVAIKSIN PTIRVIGVQS ENVHGMAASF HSGEITTHRT TGTLADGCDV
     SRPGNLTYEI VRELVDDIVL VSEDEIRNSM IALIQRNKVV TEGAGALACA ALLSGKLDQY
     IQNRKTVSII SGGNIDLSRV SQITGFVDA