Peptide Backbone Editing via Post-Translational O to C Acyl Shift.

Despite tremendous efforts to engineer translational machinery, replacing the encoded peptide backbone with new-to-nature structures remains a significant challenge. C, H, O, and N are the elements of life, yet ribosomes are capable of forming only C-N bonds as amides, C-O bonds as esters, and C-S bonds as thioesters. There is no current strategy to site-selectively form C-C bonds as ketones embedded in the backbones of ribosomal products.