(a) C6′-amination and C2′-deamination reactions respectively catalyzed by GenQ-GenB1 (blue arrows) and GenJ-GenK2 (purple arrows) interconnects the intermediates to GB. The second glycosylation catalyzed by GenM2, C3″-methylamination catalyzed by GenD2-GenS2-GenN, and C4″ methylation steps catalyzed by GenD1 are indicated by red, green, and pink arrows, respectively. (b–i) Chromatograms of GenQ-GenB1-catalyzed production of JI-20A from GX2 (b), 6′AGA2 from GA2 (c), 6′AGA from GA (d), 6′A2′DGA2 from 2′DGA2 (e), 6′A2′DGA from 2′DGA (f), GB from 2′DGX2 (g), NM from PM (h), and 2′DNM from 2′DPM (i). Lower chromatograms show the reactions without enzymes as controls. The dotted line in the upper chromatograms indicates the remaining substrate. Chromatograms show representative results of n>5 independent reactions.