Crystal structure of Delta1-tetrahydrocannabinolic acid synthase from

Shoyama, Yoshinari; Tamada, Taro; Takeuchi, Ayako*; Taura, Futoshi*; Shoyama, Yukihiro*; Morimoto, Satoshi*; Kuroki, Ryota

1-Tetrahydrocannabinolic acid (THCA) synthase is the enzyme that catalyzes oxidative cyclization of cannabigerolic acid into THCA, the precursor of Delta1-tetrahydrocannabinol. In order to investigate the structure-function relationship of THCA synthase, this enzyme was overproduced in insect cells, purified and finally crystallized in 0.1 M HEPES buffer pH 7.5 containing 1.4 M sodium citrate. The crystal diffracted to 2.8 A resolution at beamline BL41XU, SPring-8. The crystal belonged to the primitive cubic space group P432, with unit-cell parameters a = b = c = 178.2 . R value of the structure model was 19.6%. Structure of THCA synthase was divided into two domains, and there was FAD of a coenzyme between domains. Based on the structural information obtained above, amino acid mutations of the four ionizable residues (H292, Y417, E442 and Y484) located in the vicinity of FAD is now in progress to clarify their contribution on its enzymatic function.