1-(2-carboxyphenylamino)-1-deoxy-D-ribulose 5-phosphate = 1-C-(3-indolyl)-glycerol 3-phosphate CO₂ H₂O (according to Swiss-Prot)

1-(2-carboxyphenylamino)-1-deoxy-D-ribulose 5-phosphate + H⁺ --> (1S,2R)-1-C-(indol-3-yl)glycerol 3-phosphate + CO₂ + H₂O (according to UniProt)