UC San Diego

Paclitaxel, as known as taxol, is a member of a large family terpenoid and it is famous for its anti-cancer properties. It was originally isolated from a large amount of yew tree tissues and is hard to synthesize chemically. Chlamydomonas reinhardtii as a microalgae whose genome could be modified easily and be cultivating environmental friendly, is producing building blocks and starting materials for an important intermediate taxa-4, 11-diene in taxol biosynthesis. Here we introduced a new taxa-4,11-diene synthase which consists of geranylgeranyl pyrophosphate synthase and taxa-

4,11-diene synthase into C. reinhardtii and tested its expression via western blots. In addition, we identified two sfp type phosphopantetheinyl transferases (PPTases) in C. reinhardtii PptC1 and PptC2. Both of them activate cognate acyl carrier protein (ACP) of the type II fatty acid synthase (FAS) while only PptC2 is able to recognize type II FAS ACP in E.coli. Moreover, there is another single type I PKS existing in C. reinhardtii and we believe PptC2 is responsible for its activation. From the results of the above described studies, we conclude that C. reinhardtii has great potential for metabolic engineering and production of high-value natural products.