Binding modes of CYP106A2 redox partners determine differences in progesterone hydroxylation product patterns

• DOI: 10.1038/s42003-018-0104-9
• Publication Date: 2018-07-24T09:49:43Z
• Authors: Tanja Sagadin; Jan L. Riehm; Mohammed Milhim; Michael C. Hutter; Rita Bernhardt
• Keywords: Hydroxylation

Natural redox partners of bacterial cytochrome P450s (P450s) are mostly unknown. Therefore, substrate conversions performed with heterologous partners; in the case CYP106A2 from Bacillus megaterium ATCC 13368, bovine adrenodoxin (Adx) and reductase (AdR). Our aim was to optimize system for improved product formation by testing 11 different combinations partners. We found that electron transfer protein 1(516-618) showed highest yield main product, 15β-hydroxyprogesterone, and, furthermore, produced a reduced amount unwanted polyhydroxylated side products. Molecular protein-protein docking indicated this is caused subtle structural changes leading alternative binding modes both enzymes. Stopped-flow measurements analyzing reduction showing substantial differences apparent rate constants supported conclusion. The study provides first time our knowledge rational explanations patterns P450 difference mode