Figure 4: (a) Plasmid map of the pMMBL004, pAloeII-1 (pMMBL004 containing PstI fragment), and pAloeII-2 (pAloeII-1 containing actII-orf4); rep: replicon; ori: origin of replication; bla: β- ; tsr: ; apr: ; oriT: origin of transfer. (b) Schematic representation of the aloesaponarin II biosynthetic pathway. Solid and dotted arrows represent presumed enzymatic and spontaneous steps, respectively. 3,8-DMAC: 3,8-dihydroxy-1-methyl-anthraquinone-2-carboxylic acid. R1 groups of aloesaponarin II and 3,8-DMAC are hydrogen and carboxylic acid, respectively. (c) Productions of aloesaponarin II and 3,8-DMAC in recombinant S. coelicolor strains. 1, S. coelicolor ΔACT/pMMBL004; 2, S. coelicolor ΔACTΔwblAΔSCO1712ΔSCO5426/pMMBL004; 3, S. coelicolor ΔACT/pAloeII-1; 4, S. coelicolor ΔACTΔwblAΔSCO1712ΔSCO5426/pAloeII-1; 5, S. coelicolor ΔACT/pAloeII-2; 6, S. coelicolor ΔACTΔwblAΔSCO1712ΔSCO5426/pAloeII-2; 7, S. coelicolor ΔACT/pAloeII-2; 8, S. coelicolor ΔACTΔwblAΔSCO1712ΔSCO5426/pAloeII-2; 1~6, liquid culture; 7~8, solid culture; ND, not detected [29].