Production of Artemisinic acid using engineered yeast

1. Production of Artemisinic acid using engineered yeast Journal Club I 7th July 09 David Roche Charles Fracchia

2. Summary • Introduction • Materials and Methods • Identifying the genes involved in Artemisinin production • Results • Concept of feedback • Discussion • How is it relevant to SB? • Conclusions

3. Introduction • Artemisinin is anti-malarial compound • Currently extracted from the wormwood plant – but not efficient or cheap enough • Copied the biosynthetic pathways into the yeast

4. Materials and Methods • Green: engineered pathways • Blue: directly upregulated • Purple: indirectly upregulated

5. Materials and Methods • Increased FPP production by upregulating FPP synthases and downregulating to convertases • Introduced ADS • Cloned P450

6. M&M: Identifying the ADS genes • They supposed that the enzymes shown in green shared common ancestor enzymes • Compared the genes using BLAST and identified one P450 gene with high homology

7. Results 50% 2x 5x

8. The concept of feedback inhibition/activation • Metabolic flux relies on regulation

9. Discussion • Increase in yield and decrease in production costs • General principle can be applied to production of other compounds, e.g. Taxol – an anti cancer drug, which is normally extracted from the Pacific yew tree. • Good example of metabolic engineering to give a useful product.

10. Discussion • Laborious process of specially engineering each step. • Not necessarily easily reproducible. To re-engineer for other compounds, must go ‘back to the drawing board.’ • Yield optimization and industrial scale-up still required to reduce prices significantly below their current level.

11. How is it relevant to SB? • Previous strategies in metabolic engineering seem more of an art with experimentation by trial-and-error. • Keasling approach to the problem was more in line with the principles of Synthetic Biology, using a logical approach for the design. • Used computational modelling to investigate the most efficient mRNA sequence for maximal compound production

12. Conclusions • Materials and Methods • Results • Concept of feedback • Discussion Duplicate genes Knockout genes Genetic insertion 50% increase for duplication 2x increase for knockout 5x increase for gene insertion Products of a reaction can control their own conversion Engineered approach to metabolic engineering. Basic method can be applied to production of other compounds.