Campus Units
Biochemistry, Biophysics and Molecular Biology
Document Type
Article
Publication Version
Published Version
Publication Date
2-24-2012
Journal or Book Title
Journal of Biological Chemistry
Volume
287
Issue
9
First Page
6159
Last Page
6168
DOI
10.1074/jbc.M111.305599
Abstract
Recent reports have revealed genomic clustering of enzymatic genes for particular biosynthetic pathways in plant specialized/secondary metabolism. Rice (Oryza sativa) carries two such clusters for production of antimicrobial diterpenoid phytoalexins, with the cluster on chromosome 2 containing four closely related/homologous members of the cytochrome P450 CYP76M subfamily (CYP76M5–8). Notably, the underlying evolutionary expansion of these CYP appears to have occurred after assembly of the ancestral biosynthetic gene cluster, suggesting separate roles. It has been demonstrated that CYP76M7 catalyzes C11α-hydroxylation of ent-cassadiene, and presumably mediates an early step in biosynthesis of the derived phytocassane class of phytoalexins. Here we report biochemical characterization of CYP76M5, -6, and -8. Our results indicate that CYP76M8 is a multifunctional/promiscuous hydroxylase, with CYP76M5 and -7 seeming to provide only redundant activity, while CYP76M6 seems to provide both redundant and novel activity, relative to CYP76M8. RNAi-mediated double knockdown of CYP76M7 and -8 suppresses elicitor inducible phytocassane production, indicating a role for these monooxygenases in phytocassane biosynthesis. In addition, our data suggests that CYP76M5, -6, and -8 may play redundant roles in production of the oryzalexin class of phytoalexins as well. Intriguingly, the preceding diterpene synthase for oryzalexin biosynthesis, unlike that for the phytocassanes, is not found in the chromosome 2 diterpenoid biosynthetic gene cluster. Accordingly, our results not only uncover a complex evolutionary history, but also further suggest some intriguing differences between plant biosynthetic gene clusters and the seemingly similar microbial operons. The implications for the underlying metabolic evolution of plants are then discussed.
Copyright Owner
The American Society for Biochemistry and Molecular Biology, Inc.
Copyright Date
2012
Language
en
File Format
application/pdf
Recommended Citation
Wang, Qiang; Hillwig, Matthew L.; Okada, Kazunori; Yamazaki, Kohei; Wu, Yisheng; Swaminathan, Sivakumar; Yamane, Hisakazu; and Peters, Reuben J., "Characterization of CYP76M5–8 Indicates Metabolic Plasticity within a Plant Biosynthetic Gene Cluster" (2012). Biochemistry, Biophysics and Molecular Biology Publications. 114.
https://lib.dr.iastate.edu/bbmb_ag_pubs/114
Included in
Agronomy and Crop Sciences Commons, Biochemistry, Biophysics, and Structural Biology Commons, Plant Breeding and Genetics Commons
Comments
This research was originally published in Journal of Biological Chemistry. Wang Q, Hillwig ML, Okada K, Yamazaki K, Wu Y, Swaminathan S, Yamane H, Peters RJ. Characterization of CYP76M5–8 indicates metabolic plasticity within a plant biosynthetic gene cluster. Journal of Biological Chemistry. 2012 Feb 24;287:6159-6168. © the American Society for Biochemistry and Molecular Biology.