Fig. 1.

Schematic illustration of isobutanol pathway (A) Pathway design for in vivo production of KIV in E. coli and in vitro production of Isobutanol in a tube. ALsS, acetolactate synthase from Bacillus subtilis; IlvC, 2-hydroxy-3-ketol-acid reductoisomerase from E. coli; IlvD, dihydroxy-acid hydratase from E. coli; KIVD, 2-keto acid decarboxylase; ADH, Alcohol dehydrogenase. (B) KIV pathway in bicistronic design (BCD) with its two Shine-Dalgarno motifs (SD1 and SD2) is shown. +1 is mRNA and 5′UTR is leader sequence. SD2 sites adhere to the BCD (Mutalik et al., 2013).