Phylogenetic debugging of a complete human biosynthetic pathway transplanted into yeast

摘要

Cross-species pathway transplantation enables insight into a biological process not possible through traditional approaches. We replaced the enzymes catalyzing the entire adenine biosynthesis pathway with the human pathway. While the ‘humanized’ yeast grew in the absence of adenine, it did so poorly. Dissection of the phenotype revealed that , the human ortholog of , showed only partial function whereas all other genes complemented fully. Suppressor analysis revealed other pathways that play a role in adenine pathway regulation. Phylogenetic analysis pointed to adaptations of enzyme regulation to endogenous metabolite level ‘setpoints’ in diverse organisms. Using DNA shuffling, we isolated specific amino acids combinations that stabilize the human protein in yeast. Thus, using adenine biosynthesis as a proof of concept, we suggest that the engineering methods used in this study as well as the debugging strategies can be utilized to transplant metabolic pathway from any origin into yeast.