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Literature summary for 4.2.1.20 extracted from

  • Tang, X.F.; Ezaki, S.; Atomi, H.; Imanaka, T.
    Biochemical analysis of a thermostable tryptophan synthase from a hyperthermophilic archaeon (2000), Eur. J. Biochem., 267, 6369-6377.
    View publication on PubMed
Search for more literature for 4.2.1.20

Cloned(Commentary)

Cloned (Comment) Organism
independent expression of alpha- and beta-subunit encoded by genes Tk-trpA and Tk-trpB in Escherichia coli Thermococcus kodakarensis

Organism

Organism UniProt Comment Textmining
Thermococcus kodakarensis
-
 hyperthermophilic archaeon, strain KOD1, alpha- and beta-subunit are encoded by genes Tk-trpA and Tk-trpB
-

Purification (Commentary)

Purification (Comment) Organism
native enzyme complex, and recombinant alpha- and beta-subunit from expression in Escherichia coli Thermococcus kodakarensis

Reaction

Reaction Comment Organism Reaction ID
L-serine + 1-C-(indol-3-yl)glycerol 3-phosphate = L-tryptophan + D-glyceraldehyde 3-phosphate + H2O also catalyses the conversion of serine and indole into tryptophan and water, and of indoleglycerol phosphate into indole and glyceraldehyde phosphate (the latter reaction was listed formerly as EC 4.2.1.8) Thermococcus kodakarensis
a

Specific Activity [micromol/min/mg]

Specific Activity Minimum [µmol/min/mg] Specific Activity Maximum [µmol/min/mg] Comment Organism
additional information
-
 activity of the prified recombinant individually expressed subunits is 10fold lower than the activity of the native enzyme complex Thermococcus kodakarensis
8.5
-
 alpha-reaction, purified enzyme complex Thermococcus kodakarensis
110
-
 overall activity, purified enzyme complex Thermococcus kodakarensis
119
-
 beta-reaction, purified enzyme complex Thermococcus kodakarensis

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
1-(indol-3-yl)glycerol 3-phosphate alpha-subunit of the bienzyme complex, alpha-reaction, the consumption of indole in the beta-reaction is necessary for optimal activity Thermococcus kodakarensis D-glyceraldehyde 3-phosphate + indole
-
 ?
L-serine + indole beta-subunit of the bienzyme complex, beta-reaction Thermococcus kodakarensis L-tryptophan + H2O
-
 ?
additional information structure-activity relationship dependent on temperature for alpha- and beta-subunit Thermococcus kodakarensis ?
-
 ?

Subunits

Subunits Comment Organism
dimer recombinant beta-subunit, SDS-PAGE and gel filtration Thermococcus kodakarensis
monomer recombinant alpha-subunit, SDS-PAGE and gel filtration Thermococcus kodakarensis
tetramer alpha2beta2 enzyme complex, SDS-PAGE and gel filtration Thermococcus kodakarensis

Temperature Optimum [°C]

Temperature Optimum [°C] Temperature Optimum Maximum [°C] Comment Organism
70
-
 alpha-reaction Thermococcus kodakarensis
80
-
 overall reaction Thermococcus kodakarensis
90
-
 beta-reaction Thermococcus kodakarensis

Temperature Range [°C]

Temperature Minimum [°C] Temperature Maximum [°C] Comment Organism
40 85 recombinant alpha-subunit shows low activity at all temperatures Thermococcus kodakarensis
70 100 recombinant beta-subunit, low activity below 70°C, increasing activity from 70°C to 100°C, at 100°C the activity is similar to the native enzyme complex Thermococcus kodakarensis

Temperature Stability [°C]

Temperature Stability Minimum [°C] Temperature Stability Maximum [°C] Comment Organism
additional information
-
 heat treatment for purification of the recombinant alpha- and beta-subunits, individually expressed, reveals that both the 2 subunits are required for stabilizationof the activity Thermococcus kodakarensis

pH Optimum

pH Optimum Minimum pH Optimum Maximum Comment Organism
7
-
 alpha-and beta-reaction Thermococcus kodakarensis
8.5
-
 overall reaction Thermococcus kodakarensis