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

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

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

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

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

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

Results 5x 2x 50%

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

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.

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.

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

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.