Metabolic Modeling Tutorial
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Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
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MetaCyc Reaction: 4.2.1.122

Superclasses: Reactions Classified By Conversion Type Simple Reactions Chemical Reactions
Reactions Classified By Substrate Small-Molecule Reactions

EC Number: 4.2.1.122

Enzymes and Genes:
tryptophan synthase, β subunit dimer Inferred from experiment : trpB ( Escherichia coli K-12 substr. MG1655 )
tryptophan synthase Inferred from experiment : TSBType2 ( Arabidopsis thaliana col )
tryptophan synthase, beta subunit Inferred from experiment : TSB1 ( Arabidopsis thaliana col )
tryptophan synthase β subunit dimer Inferred from experiment : trpB ( Thermococcus kodakarensis )
tryptophan synthase β2 dimer Inferred from experiment : trpB2 ( Thermotoga maritima )
tryptophan synthase β1 dimer Inferred from experiment : trpB1 ( Thermotoga maritima )

Sub-reaction of:
4.2.1.20: (1S,2R)-1-C-(indol-3-yl)glycerol 3-phosphate + L-serine → L-tryptophan + D-glyceraldehyde 3-phosphate + H2O

In Pathway: tryptophan biosynthesis

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

Mass balance status: Balanced.

Enzyme Commission Primary Name: tryptophan synthase (indole-salvaging)

Enzyme Commission Synonyms: tryptophan synthase β2

Standard Gibbs Free Energy (ΔrG in kcal/mol): -15.4869995 Inferred by computational analysis [Latendresse13]

Enzyme Commission Summary:
Most mesophilic bacteria have a multimeric tryptophan synthase complex (EC 4.2.1.20) that forms L-tryptophan from L-serine and 1-C-(indol-3-yl)glycerol 3-phosphate via an indole intermediate. This intermediate, which is formed by the α subunits, is transferred in an internal tunnel to the β units, which convert it to tryptophan. In thermophilic organisms the high temperature enhances diffusion and causes the loss of indole. This enzyme, which does not combine with the α unit to form a complex, salvages the lost indole back to L-tryptophan. It has a much lower Km for indole than the β subunit of EC 4.2.1.20.

Citations: [Hettwer02, Yee96]

Gene-Reaction Schematic: ?

Unification Links: KEGG:R00674 , Rhea:26434

Relationship Links: BRENDA:EC:4.2.1.122 , ENZYME:EC:4.2.1.122 , IUBMB-ExplorEnz:EC:4.2.1.122

Credits:
Revised 09-Apr-2011 by Caspi R , SRI International


References

Hettwer02: Hettwer S, Sterner R (2002). "A novel tryptophan synthase beta-subunit from the hyperthermophile Thermotoga maritima. Quaternary structure, steady-state kinetics, and putative physiological role." J Biol Chem 277(10);8194-201. PMID: 11756459

Latendresse13: Latendresse M. (2013). "Computing Gibbs Free Energy of Compounds and Reactions in MetaCyc."

Yee96: Yee MC, Horn V, Yanofsky C (1996). "On the role of helix 0 of the tryptophan synthetase alpha chain of Escherichia coli." J Biol Chem 271(25);14754-63. PMID: 8662916


Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by SRI International Pathway Tools version 18.5 on Tue Nov 25, 2014, biocyc13.