Figure 6.

Pattern of label incorporation and transfer during the reactions catalyzed by ACMR. ACM and ACR are the monooxygenase and the reductase functionalities of ACMR. ^■H, label originally present at position C(5) of the substrate AB-CoA; *H, label originating from [4R-²H]NAD²H; and ^●H, label originating from solvent ²H₂O. The dashed arrows indicate the steps involving reversal of hydrogenation and that of aromatization of the intermediate, which occur under limiting NADH concentrations (15, 21). For details of the first step catalyzed by the ACM functionality, see Fig. 7 legend.