Fig. 4: Analysis of triptolide pathway and metabolic engineering.

a Three reactions presumably catalyzed by CYP728B70 to convert miltiradiene to dehydroabietic acid. b Establishing the metabolic pathways in yeast for production of diterpene alcohols and acids. In module 1, rox1, ypl062w, yjl06w4 were knocked out, and ERG9 was down-regulated, and tHMG1, ERG20, BTS1, SaGGPPS were overexpressed to improve the production of GGPP. In module 2, double SmMS-SmCPS1 fusion modules were introduced into the yeast chromosome for the production of miltiradiene. Co-expression of TwCYP728B70 and TwCPR3 leads to the observed production of the derived alcohols and acids.