IODOTYROSINE DEHALOGENASE, AN ENZYME REQUIRED FOR IODINE SALVAGE

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 碘在生物学中的需要几乎完全限于其在甲状腺激素中的作用。 甲状腺碘的再循环对于维持适当的激素水平至关重要。 黄蛋白碘酪氨酸脱碘酶（IYD）从甲状腺激素生物合成的副产物（单碘和二碘酪氨酸、MIT和DIT）中回收碘。 IYD脱碘机制的最初提议包括活性位点半胱氨酸对碘基的亲核攻击。 虽然这种机制有很强的优先权，定点诱变证明这是错误的。结合MIT和DIT的IYD的结构被寻求以阐明该酶的酶促机制。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The need for iodide in biology is almost exclusively limited to its role in thyroid hormones. Recycling of thyroidal iodide is critical for maintaining proper hormone levels. The flavoprotein iodotyrosine deiodinase (IYD) salvages iodide from byproducts (mono- and diiodotyrosine, MIT and DIT) of thyroid hormone biosynthesis. The original proposal for the deiodination mechanism of IYD included a nucleophilic attack of the iodo group by an active site cysteine. Although this proposed mechanism has strong precedence, site-directed mutagenesis proved this wrong. Structures of IYD with bound MIT and DIT were sought to elucidate the enzymatic mechanism of this enzyme.