ID   THRC_ECOLI              Reviewed;         428 AA.
AC   P00934; Q6LEK8;
DT   21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT   21-JUL-1986, sequence version 1.
DT   10-JUN-2026, entry version 193.
DE   RecName: Full=Threonine synthase;
DE            Short=TS;
DE            EC=4.2.3.1;
GN   Name=thrC; OrderedLocusNames=b0004, JW0003;
OS   Escherichia coli (strain K12).
OC   Bacteria; Pseudomonadati; Pseudomonadota; Gammaproteobacteria;
OC   Enterobacterales; Enterobacteriaceae; Escherichia.
OX   NCBI_TaxID=83333;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=6316258; DOI=10.1093/nar/11.21.7331;
RA   Parsot C., Cossart P., Saint-Girons I., Cohen G.N.;
RT   "Nucleotide sequence of thrC and of the transcription termination region of
RT   the threonine operon in Escherichia coli K12.";
RL   Nucleic Acids Res. 11:7331-7345(1983).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=K12;
RX   PubMed=1630901; DOI=10.1093/nar/20.13.3305;
RA   Yura T., Mori H., Nagai H., Nagata T., Ishihama A., Fujita N., Isono K.,
RA   Mizobuchi K., Nakata A.;
RT   "Systematic sequencing of the Escherichia coli genome: analysis of the
RT   0-2.4 min region.";
RL   Nucleic Acids Res. 20:3305-3308(1992).
RN   [3]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=K12 / MG1655 / ATCC 47076;
RX   PubMed=7610040; DOI=10.1093/nar/23.12.2105;
RA   Burland V.D., Plunkett G. III, Sofia H.J., Daniels D.L., Blattner F.R.;
RT   "Analysis of the Escherichia coli genome VI: DNA sequence of the region
RT   from 92.8 through 100 minutes.";
RL   Nucleic Acids Res. 23:2105-2119(1995).
RN   [4]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=K12 / MG1655 / ATCC 47076;
RX   PubMed=9278503; DOI=10.1126/science.277.5331.1453;
RA   Blattner F.R., Plunkett G. III, Bloch C.A., Perna N.T., Burland V.,
RA   Riley M., Collado-Vides J., Glasner J.D., Rode C.K., Mayhew G.F.,
RA   Gregor J., Davis N.W., Kirkpatrick H.A., Goeden M.A., Rose D.J., Mau B.,
RA   Shao Y.;
RT   "The complete genome sequence of Escherichia coli K-12.";
RL   Science 277:1453-1462(1997).
RN   [5]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=K12 / W3110 / ATCC 27325 / DSM 5911;
RX   PubMed=16738553; DOI=10.1038/msb4100049;
RA   Hayashi K., Morooka N., Yamamoto Y., Fujita K., Isono K., Choi S.,
RA   Ohtsubo E., Baba T., Wanner B.L., Mori H., Horiuchi T.;
RT   "Highly accurate genome sequences of Escherichia coli K-12 strains MG1655
RT   and W3110.";
RL   Mol. Syst. Biol. 2:E1-E5(2006).
RN   [6]
RP   PROTEIN SEQUENCE OF 1-12.
RC   STRAIN=K12 / EMG2;
RX   PubMed=9298646; DOI=10.1002/elps.1150180807;
RA   Link A.J., Robison K., Church G.M.;
RT   "Comparing the predicted and observed properties of proteins encoded in the
RT   genome of Escherichia coli K-12.";
RL   Electrophoresis 18:1259-1313(1997).
RN   [7]
RP   PROTEIN SEQUENCE OF 1-4.
RC   STRAIN=K12 / W3110 / ATCC 27325 / DSM 5911;
RX   PubMed=9600841; DOI=10.1006/jmbi.1998.1726;
RA   Wilkins M.R., Gasteiger E., Tonella L., Ou K., Tyler M., Sanchez J.-C.,
RA   Gooley A.A., Walsh B.J., Bairoch A., Appel R.D., Williams K.L.,
RA   Hochstrasser D.F.;
RT   "Protein identification with N and C-terminal sequence tags in proteome
RT   projects.";
RL   J. Mol. Biol. 278:599-608(1998).
RN   [8]
RP   FUNCTION, CATALYTIC ACTIVITY, COFACTOR, SUBSTRATE SPECIFICITY, ACTIVITY
RP   REGULATION, AND KINETIC PARAMETERS.
RX   PubMed=7907888; DOI=10.1021/bi00177a035;
RA   Laber B., Gerbling K.P., Harde C., Neff K.H., Nordhoff E., Pohlenz H.D.;
RT   "Mechanisms of interaction of Escherichia coli threonine synthase with
RT   substrates and inhibitors.";
RL   Biochemistry 33:3413-3423(1994).
RN   [9]
RP   X-RAY CRYSTALLOGRAPHY (2.2 ANGSTROMS).
RA   Omi R., Goto M., Miyahara I., Mizuguchi H., Hayashi H., Kagamiyama H.,
RA   Hirotsu K.;
RT   "Crystal structure of threonine synthase from Escherichia coli.";
RL   Submitted (FEB-2009) to the PDB data bank.
CC   -!- FUNCTION: Catalyzes the gamma-elimination of phosphate from L-
CC       phosphohomoserine and the beta-addition of water to produce L-
CC       threonine. To a lesser extent, is able to slowly catalyze the
CC       deamination of L-threonine into alpha-ketobutyrate and that of L-serine
CC       and 3-chloroalanine into pyruvate. Is also able to rapidly convert
CC       vinylglycine to threonine, which proves that the pyridoxal p-quinonoid
CC       of vinylglycine is an intermediate in the TS reaction.
CC       {ECO:0000269|PubMed:7907888}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=O-phospho-L-homoserine + H2O = L-threonine + phosphate;
CC         Xref=Rhea:RHEA:10840, ChEBI:CHEBI:15377, ChEBI:CHEBI:43474,
CC         ChEBI:CHEBI:57590, ChEBI:CHEBI:57926; EC=4.2.3.1;
CC         Evidence={ECO:0000269|PubMed:7907888};
CC   -!- COFACTOR:
CC       Name=pyridoxal 5'-phosphate; Xref=ChEBI:CHEBI:597326;
CC         Evidence={ECO:0000269|PubMed:7907888};
CC   -!- ACTIVITY REGULATION: Is competitively inhibited by L-threo-3-
CC       hydroxyhomoserine phosphate. {ECO:0000269|PubMed:7907888}.
CC   -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC       Kinetic parameters:
CC         KM=0.5 mM for O-phospho-L-homoserine {ECO:0000269|PubMed:7907888};
CC         Vmax=9.3 umol/min/mg enzyme {ECO:0000269|PubMed:7907888};
CC   -!- PATHWAY: Amino-acid biosynthesis; L-threonine biosynthesis; L-threonine
CC       from L-aspartate: step 5/5.
CC   -!- SIMILARITY: Belongs to the threonine synthase family. {ECO:0000305}.
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DR   EMBL; U14003; AAA97303.1; -; Genomic_DNA.
DR   EMBL; J01706; AAA83916.1; -; Genomic_DNA.
DR   EMBL; U00096; AAC73115.1; -; Genomic_DNA.
DR   EMBL; AP009048; BAB96581.1; -; Genomic_DNA.
DR   PIR; A01157; SYECR.
DR   RefSeq; NP_414545.1; NC_000913.3.
DR   RefSeq; WP_000781074.1; NZ_CP009789.1.
DR   PDB; 1VB3; X-ray; 2.20 A; A=1-428.
DR   AlphaFoldDB; P00934; -.
DR   SMR; P00934; -.
DR   BioGRID; 4261935; 248.
DR   BioGRID; 849584; 1.
DR   DIP; DIP-10993N; -.
DR   FunCoup; P00934; 613.
DR   IntAct; P00934; 4.
DR   STRING; 511145.b0004; -.
DR   jPOST; P00934; -.
DR   PaxDb; 511145-b0004; -.
DR   EnsemblBacteria; AAC73115; AAC73115; b0004.
DR   GeneID; 945198; -.
DR   KEGG; ecj:JW0003; -.
DR   KEGG; eco:b0004; -.
DR   KEGG; ecoc:C3026_00020; -.
DR   PATRIC; fig|1411691.4.peg.2279; -.
DR   EchoBASE; EB0993; -.
DR   eggNOG; COG0498; Bacteria.
DR   HOGENOM; CLU_015170_0_0_6; -.
DR   InParanoid; P00934; -.
DR   OMA; KGYLCEP; -.
DR   OrthoDB; 9763107at2; -.
DR   PhylomeDB; P00934; -.
DR   BioCyc; EcoCyc:THRESYN-MONOMER; -.
DR   BioCyc; MetaCyc:THRESYN-MONOMER; -.
DR   BRENDA; 4.2.3.1; 2026.
DR   SABIO-RK; P00934; -.
DR   UniPathway; UPA00050; UER00065.
DR   EvolutionaryTrace; P00934; -.
DR   PRO; PR:P00934; -.
DR   Proteomes; UP000000625; Chromosome.
DR   AbasyAtlas; P00934; -.
DR   GO; GO:0005829; C:cytosol; IDA:EcoCyc.
DR   GO; GO:0030170; F:pyridoxal phosphate binding; IEA:InterPro.
DR   GO; GO:0004795; F:threonine synthase activity; IDA:EcoCyc.
DR   GO; GO:0009088; P:L-threonine biosynthetic process; IMP:EcoCyc.
DR   CDD; cd01560; Thr-synth_2; 1.
DR   FunFam; 3.40.50.1100:FF:000026; Threonine synthase; 1.
DR   FunFam; 3.90.1380.10:FF:000001; Threonine synthase; 1.
DR   Gene3D; 3.40.50.1100; -; 2.
DR   Gene3D; 3.90.1380.10; Threonine synthase, N-terminal domain; 1.
DR   InterPro; IPR000634; Ser/Thr_deHydtase_PyrdxlP-BS.
DR   InterPro; IPR029144; Thr_synth_N.
DR   InterPro; IPR037158; Thr_synth_N_sf.
DR   InterPro; IPR004450; Thr_synthase-like.
DR   InterPro; IPR051166; Threonine_Synthase.
DR   InterPro; IPR001926; TrpB-like_PALP.
DR   InterPro; IPR036052; TrpB-like_PALP_sf.
DR   NCBIfam; TIGR00260; thrC; 1.
DR   PANTHER; PTHR42690; THREONINE SYNTHASE FAMILY MEMBER; 1.
DR   PANTHER; PTHR42690:SF1; THREONINE SYNTHASE-LIKE 2; 1.
DR   Pfam; PF00291; PALP; 1.
DR   Pfam; PF14821; Thr_synth_N; 1.
DR   SUPFAM; SSF53686; Tryptophan synthase beta subunit-like PLP-dependent enzymes; 1.
DR   PROSITE; PS00165; DEHYDRATASE_SER_THR; 1.
DR   PDBsum; 1VB3; -.
PE   1: Evidence at protein level;
KW   3D-structure; Amino-acid biosynthesis; Direct protein sequencing; Lyase;
KW   Pyridoxal phosphate; Reference proteome; Threonine biosynthesis.
FT   CHAIN           1..428
FT                   /note="Threonine synthase"
FT                   /id="PRO_0000185631"
FT   MOD_RES         107
FT                   /note="N6-(pyridoxal phosphate)lysine"
FT                   /evidence="ECO:0000250"
FT   STRAND          3..5
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   STRAND          8..13
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   HELIX           15..21
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   HELIX           25..27
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   STRAND          30..34
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   HELIX           40..46
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   HELIX           51..63
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   HELIX           64..66
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   HELIX           69..79
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   STRAND          86..90
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   STRAND          93..97
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   HELIX           107..121
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   TURN            122..124
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   STRAND          127..132
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   STRAND          134..136
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   HELIX           137..144
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   TURN            145..147
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   STRAND          151..158
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   HELIX           164..171
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   STRAND          177..184
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   HELIX           186..195
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   HELIX           196..198
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   HELIX           200..206
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   HELIX           216..221
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   HELIX           224..230
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   TURN            235..239
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   STRAND          240..246
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   HELIX           251..261
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   STRAND          267..273
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   HELIX           278..285
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   HELIX           290..293
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   HELIX           299..301
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   HELIX           309..318
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   HELIX           323..325
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   STRAND          326..330
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   HELIX           333..345
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   HELIX           352..362
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   STRAND          370..375
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   HELIX           379..382
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   HELIX           383..390
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   HELIX           395..397
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   HELIX           398..404
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   STRAND          411..415
FT                   /evidence="ECO:0007829|PDB:1VB3"
FT   HELIX           417..424
FT                   /evidence="ECO:0007829|PDB:1VB3"
SQ   SEQUENCE   428 AA;  47114 MW;  5F7C20BE00B437E2 CRC64;
     MKLYNLKDHN EQVSFAQAVT QGLGKNQGLF FPHDLPEFSL TEIDEMLKLD FVTRSAKILS
     AFIGDEIPQE ILEERVRAAF AFPAPVANVE SDVGCLELFH GPTLAFKDFG GRFMAQMLTH
     IAGDKPVTIL TATSGDTGAA VAHAFYGLPN VKVVILYPRG KISPLQEKLF CTLGGNIETV
     AIDGDFDACQ ALVKQAFDDE ELKVALGLNS ANSINISRLL AQICYYFEAV AQLPQETRNQ
     LVVSVPSGNF GDLTAGLLAK SLGLPVKRFI AATNVNDTVP RFLHDGQWSP KATQATLSNA
     MDVSQPNNWP RVEELFRRKI WQLKELGYAA VDDETTQQTM RELKELGYTS EPHAAVAYRA
     LRDQLNPGEY GLFLGTAHPA KFKESVEAIL GETLDLPKEL AERADLPLLS HNLPADFAAL
     RKLMMNHQ
//