A switch between one- and two-electron chemistry of the human flavoprotein iodotyrosine deiodinase is controlled by substrate.

ABSTRACT: Reductive dehalogenation is not typical of aerobic organisms but plays a significant role in iodide homeostasis and thyroid activity. The flavoprotein iodotyrosine deiodinase (IYD) is responsible for iodide salvage by reductive deiodination of the iodotyrosine derivatives formed as byproducts of thyroid hormone biosynthesis. Heterologous expression of the human enzyme lacking its N-terminal membrane anchor has allowed for physical and biochemical studies to identify the role of substrate in controlling the active site geometry and flavin chemistry. Crystal structures of human IYD and its complex with 3-iodo-l-tyrosine illustrate the ability of the substrate to provide multiple interactions with the isoalloxazine system of FMN that are usually provided by protein side chains. Ligand binding

SUBMITTER: Hu J 

PROVIDER: S-EPMC4281760 | biostudies-literature | 2015 Jan

REPOSITORIES: biostudies-literature