Kautschukbaum
Commonly studied ("S")-selective hydroxynitrile lyases include MeHNL from "Manihot esculenta" and HbHNL from "Hevea brasiliensis". ("R")-selective hydroxynitrile lyases have also been found to exist in "Arabidopsis thaliana" (AtHNL). AtHNL is thought to catalyze this reaction by a different mechanism.