PMID: 29942080

Authors:

Li J, Griffith WP, Davis I, Shin I, Wang J, Li F, Wang Y, Wherritt DJ, Liu A

Title:

Cleavage of a carbon-fluorine bond by an engineered cysteine dioxygenase.

Journal:

Nat Chem Biol. 2018 Jun 25. pii: 10.1038/s41589-018-0085-5. doi:, 10.1038/s41589-018-0085-5.

Abstract:

Cysteine dioxygenase (CDO) plays an essential role in sulfur metabolism by regulating homeostatic levels of cysteine. Human CDO contains a post-translationally generated Cys93-Tyr157 cross-linked cofactor. Here, we investigated this Cys-Tyr cross-linking by incorporating unnatural tyrosines in place of Tyr157 via a genetic method. The catalytically active variants were obtained with a thioether bond between Cys93 and the halogen-substituted Tyr157, and we determined the crystal structures of both wild-type and engineered CDO variants in the purely uncross-linked form and with a mature cofactor. Along with mass spectrometry and (19)F NMR, these data indicated that the enzyme could catalyze oxidative C-F or C-Cl bond cleavage, resulting in a substantial conformational change of both Cys93 and Tyr157 during cofactor assembly. These findings provide insights into the mechanism of Cys-Tyr cofactor biogenesis and may aid the development of bioinspired aromatic carbon-halogen bond activation.