STRUCTURE AND DOMAIN MOTIONS RELEVANT TO INTRAMOLECULAR ELECTRON TRANSFER IN SUL

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。 含钼酶广泛存在，催化与分子内电子转移（IET）偶联的原子转移反应。 亚硫酸盐氧化酶是钼酶主要家族的典型成员，在周转过程中以约2000 s^-1的速率进行IET。与唯一的例外亚硫酸氧化酶，所有钼酶的晶体结构显示分离的电子供体和受体网站以及在预期范围内的IET。然而，对于亚硫酸盐氧化酶，晶体结构显示在C-末端结构域中的Mo供体位点和N-末端结构域中的电子接受基团之间存在约32 <$的大分离。如此大的间隔似乎排除了所观察到的速率下的国际排放贸易。已经提出N-末端结构域与较大C-末端结构域的对接（更紧凑的构象）以促进IET，但是对此没有实验证据。 拟议的研究旨在提供这种证据。

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. Molybdenum-containing enzymes are widespread, catalyzing atom transfer reactions coupled to intramolecular electron transfer (IET). Sulfite oxidase is the prototypical member of one major family of Mo enzymes, and carries out IET during turnover with a rate of ~2000 s^-1. With the sole exception of sulfite oxidase, all Mo enzyme crystal structures show separations of electron donor and acceptor sites well within the expected range for IET. For sulfite oxidase, however, crystal structures show large separations of ~32 ¿ between the Mo donor site in the C-terminal domain and the electron-accepting group in the N-terminal domain. Such large separation would appear to preclude IET at the rates observed. Docking of the N-terminal domain with the larger C-terminal domain (a more compact conformation) has been proposed to facilitate IET however there is no experimental evidence for this. The proposed study seeks to provide such evidence.