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EC 4.2.1.122 Details
show Brenda entryEC number
4.2.1.122
Accepted name
tryptophan synthase (indole-salvaging)
Reaction
L-serine + indole = L-tryptophan + H2O
Other name(s)
tryptophan synthase β2
Systematic name
L-serine hydro-lyase [adding indole, L-tryptophan-forming]
Comment
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.
History
created 2011
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1 Oxidoreductases
1.1 Acting on the CH-OH group of donors
1.3.99.9 created 1976, deleted 2002
