Carrier Protein-Free Chemo-Enzymatic Synthesis of Arylomycin A2 and Structural Characterization of the Cytochrome P450 AryC

The functional and structural evaluation of AryC, the cytochrome P450 performing biaryl coupling in biosynthetic arylomycin assembly, and its application in the chemo-enzymatic synthesis of arylomycin A2 is described. AryC efficiently converts free substrates without the requirement of any protein interaction partner, likely enabled by a strongly hydrophobic cavity at the surface of AryC pointing to the substrate tunnel. The resulting reactivity of AryC is unprecedented in cytochrome P450-mediated biaryl construction in non-ribosomal peptides, in which PCP-tethering so far was crucial both in vivo and in vitro. Our work thus provides a basis for the development of general biocatalytic platforms for the efficient biocatalytic synthesis of biaryl peptide antibiotics.