Heterologous production of natural products in the host S. venezuelae. (A) Chemical structures of representative natural products. Gentamicin A2; Hopene; Pseudoribostamycin; and Tylactone and its glycosylated derivative 5-O-mycaminosyl tylactone. (B) New kanamycins generated by the substrate flexibilities of the glycosyltranseferases KanF and KanE. New catalytic route of KanF or KanE is highlighted in blue or orange, respectively; and the corresponding new sugar donor is marked by an asterisk. 2-DOS, 2-deoxystreptamine; G6P, glucose-6-phosphate; UDP-Glc, UDP-d-glucose; UDP-GlcNAc, UDP-N-acetlyglucosamine; UDP-Kns, UDP-d-kanosamine.