Fig. 4

Improve the targeted product specificity by mutagenesis to adjust the relative position between the catalytic active site heme and the substrate. Heme in the catalytic active site of CYP11B1 was represented by orange, while the substrate 17-OHP was represented by grey. All the mutated residues were highlighted in purple. a The structural model of CYP11B1_Hs mutant1/17-OHP complex. The orange and grey arrows indicated the moving direction of the heme and the substrate, respectively. b The strategy for type I mutagenesis including F381A/L382S, F381A/L382T, R110A and R384A. c The strategy for type II mutagenesis as I488L. d The transformation rate of 21-DF and product/by-product ratio achieved by the designed mutagenesis