Premium
Cofactor Biogenesis in Cysteamine Dioxygenase: C−F Bond Cleavage with Genetically Incorporated Unnatural Tyrosine
Author(s) -
Wang Yifan,
Griffith Wendell P.,
Li Jiasong,
Koto Teruaki,
Wherritt Daniel J.,
Fritz Elizabeth,
Liu Aimin
Publication year - 2018
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201803907
Subject(s) - chemistry , dioxygenase , cofactor , cysteine , stereochemistry , tyrosine , cysteamine , biochemistry , thioether , bond cleavage , biogenesis , amino acid , enzyme , gene , catalysis
Abstract Cysteamine dioxygenase (ADO) is a thiol dioxygenase whose study has been stagnated by the ambiguity as to whether or not it possesses an anticipated protein‐derived cofactor. Reported herein is the discovery and elucidation of a Cys‐Tyr cofactor in human ADO, crosslinked between Cys220 and Tyr222 through a thioether (C−S) bond. By genetically incorporating an unnatural amino acid, 3,5‐difluoro‐tyrosine (F 2 ‐Tyr), specifically into Tyr222 of human ADO, an autocatalytic oxidative carbon–fluorine bond activation and fluoride release were identified by mass spectrometry and 19 F NMR spectroscopy. These results suggest that the cofactor biogenesis is executed by a powerful oxidant during an autocatalytic process. Unlike that of cysteine dioxygenase, the crosslinking results in a minimal structural change of the protein and it is not detectable by routine low‐resolution techniques. Finally, a new sequence motif, C‐X‐Y‐Y(F), is proposed for identifying the Cys‐Tyr crosslink.