ID 4.2.1.128 DE lupan-3beta,20-diol synthase. CA lupan-3beta,20-diol = (S)-2,3-epoxysqualene + H2O. CC -!- The reaction occurs in the reverse direction. CC -!- The recombinant enzyme from Arabidopsis thaliana gives a 1:1 mixture CC of lupeol and lupan-3beta,20-diol with small amounts of beta-amyrin, CC germanicol, taraxasterol and psi-taraxasterol. CC -!- See EC 5.4.99.41. DR Q9C5M3, LUP1_ARATH ; //