Fig. 7
a Indirubin titer of various mutants of bFMO in vivo. b Enzyme residual activities of various mutants relative to the wild-type (1 ×) toward indole. c Hydrogen bond between Y207 and N291 is indicated by green dashed line in wild-type bFMO. d Distance between Y207 (purple) and T291 (green) is indicated by yellow dashed lines in N291T mutant. The substrate tunnel shown in balls in wild-type bFMO (e) and the N291T mutant (f) was identified by CAVER 3.0. Statistical analysis was performed using the Student’s t test (one-tailed; two-sample unequal variance; *p < 0.05, **p < 0.01, ***p < 0.001). All data represent the mean of n = 3 biologically independent samples and error bars show the standard deviation