EPR STUDIES OF AN FUMARATE NITRATE REDUCTION

铁硫蛋白，FNR（富马酸硝酸盐还原）是一种 全局基因调控因子，控制100多个基因的转录 其产物促进大肠杆菌适应的基因 在限氧条件下生长。 研究表明， 四铁四硫簇转化为二铁二硫 簇暴露于氧气中，这一过程会减少 DNA 结合 FNR。 低温、液氮和液氦温度， 对野生型 FNR 和稳定的突变体样品进行 EPR 氧化损伤，L28H，已用一氧化氮治疗。 两者都 样品表现出 g=2.04 信号归因于 铁-硫醇-二亚硝基络合物。 没有观察到任何信号 归因于 Fe-S 团簇。

The iron sulfur protein, FNR (fumarate nitrate reduction) is a global gene regulator, controlling the transcription of more than 100 genes whose products facilitate the adaptation of Eschericia coli for growth under oxygen limiting conditions. Studies have shown that the four iron-four sulfur cluster is converted into a 2 iron-2 sulfur cluster on exposure to oxygen, a process that decreases DNA binding by FNR. Low temperature, liquid nitrogen and liquid helium temperatures, EPR was performed on samples of wild type FNR and a mutant stable to oxidative damage, L28H, that had been treated with nitric oxide. Both samples exhibited the g=2.04 signal attributed to an iron-thiol-dinitrosyl complex. No signals were observed that could be attributed to Fe-S clusters.