Flavoprotein Iodotyrosine Deiodinase Functions without Cysteine Residues

Abstract

Iodotyrosine deiodinase provides a new precedent for flavin-dependent dehalogenation. Iodotyrosine deiodinase requires no standard redox-active amino acid to promote reductive deiodination of diiodotyrosine despite the precedence for such residues in other enzymes that catalyze analogous reactions. Three cysteines present in the native mammalian enzyme could be removed without significant loss of catalytic activity.