ID   TDCB_STAAR              Reviewed;         346 AA.
AC   Q6GGX0;
DT   15-MAY-2007, integrated into UniProtKB/Swiss-Prot.
DT   19-JUL-2004, sequence version 1.
DT   03-AUG-2022, entry version 100.
DE   RecName: Full=L-threonine dehydratase catabolic TdcB;
DE            EC=4.3.1.19;
DE   AltName: Full=Threonine deaminase;
GN   Name=tdcB; OrderedLocusNames=SAR1450;
OS   Staphylococcus aureus (strain MRSA252).
OC   Bacteria; Firmicutes; Bacilli; Bacillales; Staphylococcaceae;
OC   Staphylococcus.
OX   NCBI_TaxID=282458;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=MRSA252;
RX   PubMed=15213324; DOI=10.1073/pnas.0402521101;
RA   Holden M.T.G., Feil E.J., Lindsay J.A., Peacock S.J., Day N.P.J.,
RA   Enright M.C., Foster T.J., Moore C.E., Hurst L., Atkin R., Barron A.,
RA   Bason N., Bentley S.D., Chillingworth C., Chillingworth T., Churcher C.,
RA   Clark L., Corton C., Cronin A., Doggett J., Dowd L., Feltwell T., Hance Z.,
RA   Harris B., Hauser H., Holroyd S., Jagels K., James K.D., Lennard N.,
RA   Line A., Mayes R., Moule S., Mungall K., Ormond D., Quail M.A.,
RA   Rabbinowitsch E., Rutherford K.M., Sanders M., Sharp S., Simmonds M.,
RA   Stevens K., Whitehead S., Barrell B.G., Spratt B.G., Parkhill J.;
RT   "Complete genomes of two clinical Staphylococcus aureus strains: evidence
RT   for the rapid evolution of virulence and drug resistance.";
RL   Proc. Natl. Acad. Sci. U.S.A. 101:9786-9791(2004).
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 (By similarity).
CC       {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   -!- 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}.
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DR   EMBL; BX571856; CAG40447.1; -; Genomic_DNA.
DR   RefSeq; WP_000210828.1; NC_002952.2.
DR   AlphaFoldDB; Q6GGX0; -.
DR   SMR; Q6GGX0; -.
DR   KEGG; sar:SAR1450; -.
DR   HOGENOM; CLU_021152_4_2_9; -.
DR   OMA; LIHPFDH; -.
DR   OrthoDB; 1876944at2; -.
DR   UniPathway; UPA00052; UER00507.
DR   Proteomes; UP000000596; Chromosome.
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..346
FT                   /note="L-threonine dehydratase catabolic TdcB"
FT                   /id="PRO_0000287328"
FT   BINDING         59..60
FT                   /ligand="AMP"
FT                   /ligand_id="ChEBI:CHEBI:456215"
FT                   /evidence="ECO:0000250"
FT   BINDING         94
FT                   /ligand="AMP"
FT                   /ligand_id="ChEBI:CHEBI:456215"
FT                   /evidence="ECO:0000250"
FT   BINDING         125..126
FT                   /ligand="AMP"
FT                   /ligand_id="ChEBI:CHEBI:456215"
FT                   /evidence="ECO:0000250"
FT   BINDING         321
FT                   /ligand="AMP"
FT                   /ligand_id="ChEBI:CHEBI:456215"
FT                   /evidence="ECO:0000250"
FT   MOD_RES         64
FT                   /note="N6-(pyridoxal phosphate)lysine"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   346 AA;  37306 MW;  A69CB839024C9C5F CRC64;
     MTTNTVTLQT AHIVSLGDIE EAKASIKPFI RRTPLIKSMY LSQSITKGNV FLKLENMQFT
     GSFKFRGASN KINHLTDEQK EKGIIAASAG NHAQGVALTA KLLGIDATIV MPETAPQAKQ
     QATKGYGAKV ILKGKNFNET RLYMEELAKE NGMTIVHPYD DKFVMAGQGT IGLEILDDIW
     NVNTVIVPVG GGGLIAGIAT ALKSFNPSIH IIGVQSENVH GMAESFYKRD LTEHRVDSTI
     ADGCDVKVPG EQTYEVVKHL VDEFILVTEE EIEHAMKDLM QRAKIITEGA GALPTAAILS
     GKINNKWLED KNVVALVSGG NVDLTRVSGV IEHGLNIADT SKGVVG