ELECTRON TRANSFER PATHWAYS/BLUE COPPER PROTEINS

反硝化细菌是管理废物的重要因素。其中一个 硝酸盐最终转化为氮气的电子转移途径 利用，为特别有效的反硝化细菌产碱 粪便假单胞菌S-6，含铜亚硝酸还原酶和蓝色 一种蛋白质，在正常情况下作为转移剂 电子到亚硝酸盐还原酶，也可以作为一种抑制剂在 氧气的存在。 我建议将蓝铜蛋白的结构确定为 氧化和还原两种形式的分辨率，使用标准 X射线衍射技术。长期目标是 了解分子水平上的电子转移，以了解它是什么 关于促进电子转移的蛋白质结构，什么？ 提供了特异性，不同的蛋白质如何利用相同的 辅因。部分序列信息和氨基酸组成 这种相对分子质量介于另外两种蓝铜之间的蓝色蛋白质 已知结构的蛋白质，塑料蓝蛋白和天青素，表明 虽然粪链霉菌蓝蛋白可能有相同的发色团，但它可能 具有不同的折叠，并且可以很好地代表 这些I型蓝铜蛋白。因此，这一结构确定将 为生物体如何溶解、利用和调节 电子转移辅因子。此外，由于它与 亚硝酸盐还原酶的定义很好，其结构也在研究中 关于，我们最终可以直接研究电子如何 传输组件相互作用。

Denitrifying bacteria are important agents in managing waste. One of the electron transfer pathways in which nitrates are converted eventually to N2 utilizes, for the particularly potent denitrifying bacteria Alcaligenes faecalis Strain S-6, a copper containing nitrite reductase, and a blue protein which while normally acting as the agent which transfers an electron to the nitrite reductase, can also act as an inhibitor in the presence of O2. I propose to determine the structure of that blue copper protein to high resolution in both the oxidized and reduced forms, using standard techniques of X-ray diffraction. The long term objectives are to understand electron transfer at a molecular level, to understand what it is about electron transfer protein structures that facilitates transfer, what provides specificity, how different proteins make use of the same cofactor. Partial sequence information and the amino acid composition of this blue protein of molecular weight intermediate to two other blue copper proteins with known structure, plastocyanin and azurin, indicates that while A. faecalis blue protein probably has the same chromophore, it may have different folding, and may well represent a structural subclass of these Type I blue copper proteins. Thus this structure determination will afford a new view of how an organism solubilizes, utilizes and regulates an electron transfer cofactor. Moreover, since its interaction with the nitrite reductase is well defined, and its structure is also being worked on, we can eventually directly examine the question of how electron transfer components interact.