Crystal structure of Delta1-tetrahydrocannabinolic acid synthase from

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

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. A single crystal suitable for X-ray diffraction measurement was obtained in 0.09 M HEPES buffer pH 7.5 containing 1.26 M sodium citrate. The crystal diffracted to 2.8 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%. Active site of THCA synthase was investigated by mutation analysis using the structural information from X-ray crystallography. It was found that Tyr484 was identified to be one of the important residues in activity of THCA synthase.