XRAY ABSORPTION SPECTROSCOPY OF METAL SUBSTITUTED IRON SULFUR CLUSTER

激烈热球菌铁氧化还原蛋白是铁氧化还原蛋白中唯一的一种， 具有单个Fe4S4簇，其中一个铁具有非硫 协同 蛋白质的一个不寻常的特征是容易与 该簇可以失去该铁以形成Fe3S4铁氧还蛋白。 的 Fe3S4铁氧还蛋白可以很容易地与Fe 2+重组，以改革铁氧还蛋白。 天然Fe4S4簇，或者与其他金属离子， 生成混合金属铁硫簇MFe 3S 4。 混合的金属铁 硫簇包含一类非常重要的金属蛋白 活跃的网站，并有相当大的兴趣。 我们建议使用XAS 系统地探测电子和物理结构的 不同的MFe3S4簇在Pyrococcus furiosus铁氧还蛋白。

Pyrococcus furiosus ferredoxin is unique among ferredoxins in having a single Fe4S4 cluster with one iron possessing non-sulfur coordination. An unusual feature of the protein is the ease with which the cluster can lose this iron to form a Fe3S4 ferredoxin. The Fe3S4 ferredoxin can readily be reconstituted with Fe2+ to reform the native Fe4S4 cluster, or alternatively with other metals ions to generate a mixed-metal iron sulfur cluster MFe3S4. Mixed metal iron sulfur clusters comprise a very important class of metalloprotein active sites and are of considerable interest. We propose to use XAS to systematically probe the electronic and physical structure of the different MFe3S4 clusters in Pyrococcus furiosus ferredoxin.