Liu Ya-Jun, Song Xiaxia, Li Yifei, Xuan Jinsong, Cui Qiu, Wang Jinfeng, Feng Yingang
Shandong Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, China.
Qingdao Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, China.
FEBS Lett. 2016 Feb;590(3):387-95. doi: 10.1002/1873-3468.12068. Epub 2016 Feb 2.
NrdH redoxin is the only hydrogen donor for ribonucleotide reductase in Mycobacterium tuberculosis. Several crystal structures of NrdH redoxins in the oxidized state from different species have been reported, but no structure of the reduced state has yet been reported. Using NMR spectroscopy, we found surprisingly that the reduced NrdH redoxin from M. tuberculosis is largely unfolded at a pH lower than the pKa of its first active site cysteine, and the structural basis of the low stability was analyzed. In addition, a single mutant of the NrdH redoxin suitable to determine the structure in the reduced state was obtained.
NrdH 氧化还原蛋白是结核分枝杆菌中核糖核苷酸还原酶的唯一氢供体。已经报道了来自不同物种的处于氧化态的NrdH氧化还原蛋白的几种晶体结构，但尚未报道还原态的结构。通过核磁共振光谱，我们惊奇地发现，来自结核分枝杆菌的还原态NrdH氧化还原蛋白在低于其第一个活性位点半胱氨酸的pKa的pH值下大部分处于未折叠状态，并分析了其低稳定性的结构基础。此外，还获得了一种适合确定还原态结构的NrdH氧化还原蛋白单突变体。
