Publication Type:Journal Article
Source:Appl Microbiol Biotechnol, Volume 99, Issue 18 (2015)
<p>The oxygenation reactions catalyzed by cytochromes P450 (CYPs) play critical roles in plant natural products biosynthesis. At the same time, CYPs are one of most challenging enzymes to functionally characterize due to the difficulty of recombinantly expressing these membrane-associated monooxygenases. In the course of investigating rice diterpenoid biosynthesis, we have developed a synthetic biology approach for functional expression of relevant CYPs in Escherichia coli. In certain cases, activity was observed for only one of two closely related paralogs although it seems clear that related reactions are required for production of the known diterpenoids. Here, we report that optimization of the recombinant expression system enabled characterization of not only these previously recalcitrant CYPs, but also discovery of additional activity relevant to rice diterpenoid biosynthesis. Of particular interest, CYP701A8 was found to catalyze 3beta-hydroxylation of syn-pimaradiene, which is presumably relevant to momilactone biosynthesis, while CYP71Z6 & 7 were found to catalyze multiple reactions, with CYP71Z6 catalyzing the production of 2alpha,3alpha-dihydroxy-ent-isokaurene via 2alpha-hydroxy-ent-isokaurene, and CYP71Z7 catalyzing the production of 3alpha-hydroxy-ent-cassadien-2-one via 2alpha-hydroxy-ent-cassadiene and ent-cassadien-2-one, which may be relevant to oryzadione and phytocassane biosynthesis, respectively.</p>
1432-0614<br/>Kitaoka, Naoki<br/>Wu, Yisheng<br/>Xu, Meimei<br/>Peters, Reuben J<br/>R01 GM076324/GM/NIGMS NIH HHS/United States<br/>Journal article<br/>Appl Microbiol Biotechnol. 2015 Mar 12.