METALLOENZYMES AND MEDICINE

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得主要资金，因此可以在其他CRISP条目中表示。所列机构为中心机构，不一定为研究者机构。临床上重要的抗生素磷霉素的生物合成途径使用催化反应的酶，在生物学上没有先例。其中之一是羟丙基膦酸环氧酶，它代表了一个新的非血红素单核铁酶亚家族。在这里，我们提出了六种X-射线结构的这种酶：在2.0 A分辨率的脱辅基酶;在2.4 A分辨率的天然Fe（II）结合形式;在1.8 A分辨率的三（羟甲基）氨基甲烷-Co（II）-酶复合物结构;在2.5 A分辨率的底物-Co（II）-酶复合物结构;和两个底物-Fe（II）-酶复合物在2.1和2.3 A分辨率。这些结构数据使我们提出这种酶如何能够识别和响应其底物的构象变化，保护在催化过程中形成的基于自由基的中间体。与其他家族成员的比较表明，为什么底物结合能够在不存在α-酮戊二酸（许多单核铁酶所需的共底物）的情况下引发铁的双氧结合，以及羟丙基膦酸环氧酶的独特环氧化反应如何发生。这项工作发表在《自然》杂志上，其中五个保藏的PDB代码（1ZZ6，1ZZ9，1ZZ7，1ZZC，1ZZB）来自NE-CAT 8-BM的数据。

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 biosynthetic pathway of the clinically important antibiotic fosfomycin uses enzymes that catalyse reactions without precedent in biology. Among these is hydroxypropylphosphonic acid epoxidase, which represents a new subfamily of non-haem mononuclear iron enzymes. Here we present six X-ray structures of this enzyme: the apoenzyme at 2.0 A resolution; a native Fe(II)-bound form at 2.4 A resolution; a tris(hydroxymethyl)aminomethane-Co(II)-enzyme complex structure at 1.8 A resolution; a substrate-Co(II)-enzyme complex structure at 2.5 A resolution; and two substrate-Fe(II)-enzyme complexes at 2.1 and 2.3 A resolution. These structural data lead us to suggest how this enzyme is able to recognize and respond to its substrate with a conformational change that protects the radical-based intermediates formed during catalysis. Comparisons with other family members suggest why substrate binding is able to prime iron for dioxygen binding in the absence of alpha-ketoglutarate (a co-substrate required by many mononuclear iron enzymes), and how the unique epoxidation reaction of hydroxypropylphosphonic acid epoxidase may occur. This work was published in Nature, with five of the deposited PDB codes (1ZZ6, 1ZZ9, 1ZZ7 1ZZC, 1ZZB) coming from data taken at NE-CAT 8-BM.