Loading a peptidyl-coenzyme A onto peptidyl carrier proteins: A novel approach in characterizing macrocyclization by thioesterase domains

A new experimental approach is reported to characterize recombinant nonribosomal peptide cyclasses that do not show activity with conventional N-acetylcysteamine (SNAC) substrates. The regioselectivity of branched-chain cyclization catalyzed by the fengycin cyclase is characterized, which displays no activity with peptidyl SNAC substrates.