EPR STUDIES OF AN FUMARATE NITRATE REDUCTION

铁硫蛋白，FNR（富马酸硝酸盐还原）是一种 全球基因调节器，控制100多个转录 基因，其产物有助于适应土方工程大肠杆菌， 在氧限制条件下生长。 研究表明 四个铁-四个硫簇合物转化为2个铁-2个硫簇合物， 在暴露于氧气时聚集，这是一个减少DNA结合的过程， FNR。 低温，液氮和液氦温度， 对野生型FNR和对FNR稳定的突变体的样品进行EPR。 氧化损伤，L28 H，已经用一氧化氮处理。 两 样品表现出g=2.04的信号，归因于 铁-硫醇-二亚硝酰络合物。 未观察到可能导致 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.