This enzyme belongs to the family of lyases, specifically the hydro-lyases, which cleave carbon-oxygen bonds. The systematic name of this enzyme class is (6R)-6-(L-erythro-1,2-dihydroxypropyl)-5,6,7,8-tetrahydro-4a-hydroxy pterin hydro-lyase [(6R)-6-(L-erythro-1,2-dihydroxypropyl)-7,8-dihydro-6H-pterin-formin g]. Other names in common use include 4alpha-hydroxy-tetrahydropterin dehydratase, pterin-4alpha-carbinolamine dehydratase, and 4a-hydroxytetrahydrobiopterin hydro-lyase.
Blau N, Ghisla S, Heizmann CW (1993). "Phenylalanine hydroxylase-stimulating protein/pterin-4 alpha-carbinolamine dehydratase from rat and human liver Purification, characterization, and complete amino acid sequence". J. Biol. Chem. 268 (7): 4828–31. PMID8444860.