Geraniol 10-hydroxylase, a cytochrome P450 enzyme involved in terpenoid indole alkaloid biosynthesis

Geraniol 10-hydroxylase (G10H) is a cytochrome P450 monooxygenase involved in the biosynthesis of iridoid monoterpenoids and several classes of monote rpenoid alkaloids found in a diverse range of plant species. Catharanthus r oseus (Madagascar periwinkle) contains monoterpenoid indole alkaloids, seve ral of which are pharmaceutically important. Vinblastine and vineristine, f or example, find widespread use as anticancer drugs. G10H is thought to pla y a key regulatory role in terpenoid indole alkaloid biosynthesis. We purif ied G10H from C roseus cells. Using degenerate PCR primers based on amino a cid sequence information we cloned the corresponding cDNA. The encoded CYP7 6B6 protein has G10H activity when expressed in C. roseus and yeast cells. The stress hormone methyljasmonate strongly induced G10h gene expression co ordinately with other terpenoid indole alkaloid biosynthesis genes in a C. roseus cell culture. (C) 2001 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.