Escherichia coli K-12 substr. MG1655 Compound: L-threonine

Abbrev Name: thr

Synonyms: T, thr, thre, L-thr, threonine, 2-amino-3-hydroxybutyric acid

Superclasses: an amino acid or its derivative an amino acid a polar amino acid an uncharged polar amino acid
an amino acid or its derivative an amino acid an alpha amino acid a standard alpha amino acid
an amino acid or its derivative an amino acid an L-amino acid

Chemical Formula: C4H9NO3

Molecular Weight: 119.12 Daltons

Monoisotopic Molecular Weight: 119.0582431604 Daltons

L-threonine compound structure

pKa 1: 2.15

pKa 2: 9.12

SMILES: CC(O)C([N+])C([O-])=O

InChI: InChI=1S/C4H9NO3/c1-2(6)3(5)4(7)8/h2-3,6H,5H2,1H3,(H,7,8)/t2-,3+/m1/s1


Unification Links: CAS:72-19-5 , ChEBI:57926 , HMDB:HMDB00167 , IAF1260:34186 , KEGG:C00188 , MetaboLights:MTBLC57926 , PubChem:6971019

Standard Gibbs Free Energy of Change Formation (ΔfG in kcal/mol): -123

Reactions known to consume the compound:

L-isoleucine biosynthesis I (from threonine) , L-threonine degradation I :
L-threonine → (2Z)-2-aminobut-2-enoate + H2O + H+

L-threonine degradation II , L-threonine degradation III (to methylglyoxal) :
L-threonine + NAD+ → 2-amino-3-oxobutanoate + NADH + H+

L-threonine degradation IV :
L-threonine → acetaldehyde + glycine

tRNA charging :
a tRNAthr + L-threonine + ATP + H+ → an L-threonyl-[tRNAthr] + AMP + diphosphate

Not in pathways:
L-threonine → 2-oxobutanoate + ammonium

Reactions known to produce the compound:

L-threonine biosynthesis :
O-phospho-L-homoserine + H2O → L-threonine + phosphate

Not in pathways:
L-alanyl-L-threonine + H2O → L-alanine + L-threonine
L-threonine 3-O-phosphate[periplasmic space] + H2O[periplasmic space]L-threonine[periplasmic space] + phosphate[periplasmic space]

Not in pathways:
a peptide with an N-terminal X-L-proline + H2O → a standard α amino acid + a peptide with an N-terminal L-proline + H+
a peptide + H2O → a standard α amino acid + a peptide
a protein + H2O → a peptide + a standard α amino acid
a protein + H2O → a peptide + a standard α amino acid
a protein + H2O → a standard α amino acid + a peptide
β-aspartyl dipeptide + H2O → L-aspartate + a standard α amino acid
a dipetide with an N-terminal L-aspartate + H2O → L-aspartate + a standard α amino acid
a tripeptide + H2O → a dipeptide + a standard α amino acid
a dipeptide with proline at the C-terminal + H2O → L-proline + a standard α amino acid
a dipeptide + H2O → 2 a standard α amino acid

Not in pathways:
a polypeptide + H2O → a polypeptide + an L-amino acid

In Reactions of unknown directionality:

Not in pathways:
L-methionine + a 2-oxo carboxylate = 2-oxo-4-methylthiobutanoate + a standard α amino acid

Not in pathways:
a 5-L-glutamyl-[peptide][periplasmic space] + an amino acid[periplasmic space] = a 5-L-glutamyl-amino acid[periplasmic space] + a peptide[periplasmic space]

In Transport reactions:
L-threonine[periplasmic space] + H+[periplasmic space]L-threonine[cytosol] + H+[cytosol] ,
L-threonine[cytosol] + H+[periplasmic space]L-threonine[periplasmic space] + H+[cytosol] ,
an L-amino acid[cytosol]an L-amino acid[periplasmic space]

Enzymes inhibited by L-threonine, sorted by the type of inhibition, are:

Inhibitor (Competitive) of: aspartate kinase [Bearer78, Wright77a, Broglie83, Jullien88, Chassagnole01] , homoserine kinase [Theze74, Burr76, Comment 1]

Inhibitor (Mechanism unknown) of: homoserine dehydrogenase [Chassagnole01]

This compound has been characterized as an alternative substrate of the following enzymes: leucine efflux transporter , transport of L-leucine , allothreonine acetaldehyde-lyase (glycine-forming)

In Growth Media: Neidhardt EZ rich defined medium , Gutnick minimal salts medium base + thr , PMA nitrogen source test + thr , PMA carbon source test + thr


Bearer78: Bearer CF, Neet KE (1978). "Threonine inhibition of the aspartokinase--homoserine dehydrogenase I of Escherichia coli. A slow transient and cooperativity of inhibition of the aspartokinase activity." Biochemistry 1978;17(17);3523-30. PMID: 28752

Broglie83: Broglie KE, Takahashi M (1983). "Fluorescence studies of threonine-promoted conformational transitions in aspartokinase I using the substrate analogue 2'(3')-O-(2,4,6-trinitrophenyl)adenosine 5'-triphosphate." J Biol Chem 1983;258(21);12940-6. PMID: 6313682

Burr76: Burr B, Walker J, Truffa-Bachi P, Cohen GN (1976). "Homoserine kinase from Escherichia coli K12." Eur J Biochem 1976;62(3);519-26. PMID: 177283

Chassagnole01: Chassagnole C, Rais B, Quentin E, Fell DA, Mazat JP (2001). "An integrated study of threonine-pathway enzyme kinetics in Escherichia coli." Biochem J 356(Pt 2);415-23. PMID: 11368768

Jullien88: Jullien M, Baudet S, Rodier F, Le Bras G (1988). "Allosteric transition of aspartokinase I-homoserine dehydrogenase I studied by time-resolved fluorescence." Biochimie 1988;70(12);1807-14. PMID: 3150686

Theze74: Theze J, Kleidman L, St Girons I (1974). "Homoserine kinase from Escherichia coli K-12: properties, inhibition by L-threonine, and regulation of biosynthesis." J Bacteriol 1974;118(2);577-81. PMID: 4364023

Wright77a: Wright JK, Takahashi M (1977). "Interaction of substrates and inhibitors with the homoserine dehydrogenase of kinase-inactivated aspartokinase I." Biochemistry 1977;16(8);1541-8. PMID: 192265

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Please cite the following article in publications resulting from the use of EcoCyc: Nucleic Acids Research 41:D605-12 2013
Page generated by SRI International Pathway Tools version 19.0 on Fri May 22, 2015, BIOCYC14B.