Metabolic Modeling Tutorial
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Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
BioCyc websites down
12/28 - 12/31
for maintenance.
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
BioCyc websites down
12/28 - 12/31
for maintenance.
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
BioCyc websites down
12/28 - 12/31
for maintenance.
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
BioCyc websites down
12/28 - 12/31
for maintenance.
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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 Mon Dec 22, 2014, BIOCYC14B.