Synergistic Binding of the Halide and Cationic Prime Substrate of l-Lysine 4-Chlorinase, BesD, in Both Ferrous and Ferryl States.

An aliphatic halogenase requires four substrates: 2-oxoglutarate (2OG), halide (Cl or Br), the halogenation target ("prime substrate"), and dioxygen. In well-studied cases, the three nongaseous substrates must bind to activate the enzyme's Fe(II) cofactor for efficient capture of O. Halide, 2OG, and (lastly) O all coordinate directly to the cofactor to initiate its conversion to a -halo-oxo-iron(IV) (haloferryl) complex, which abstracts hydrogen (H) from the non-coordinating prime substrate to enable radicaloid carbon-halogen coupling.

Synergistic Binding of the Halide and Cationic Prime Substrate of the l-Lysine 4-Chlorinase, BesD, in Both Ferrous and Ferryl States.

An aliphatic halogenase requires four substrates: 2-oxoglutarate (2OG), halide (Cl or Br ), the halogenation target ("prime substrate"), and dioxygen. In well-studied cases, the three non-gaseous substrates must bind to activate the enzyme's Fe(II) cofactor for efficient capture of O . Halide, 2OG, and (lastly) O all coordinate directly to the cofactor to initiate its conversion to a -halo-oxo-iron(IV) (haloferryl) complex, which abstracts hydrogen (H•) from the non-coordinating prime substrate to enable radicaloid carbon-halogen coupling.