College of Pharmaceutical Sciences, Ritsumeikan University , Noji-higashi 1-1-1, Kusatsu 525-8577, Japan.
Biochemistry. 2014 Jan 28;53(3):447-9. doi: 10.1021/bi401617n. Epub 2014 Jan 10.
We present the nuclear Overhauser effect-based structure determination of the Q41N variant of ubiquitin at 2500 bar, where the alternatively folded N2 state is 97% populated. This allows us to characterize the structure of the "pure" N2 state of ubiquitin. The N2 state shows a substantial change in the orientation of strand β5 compared to that of the normal folded N1 state, which matches the changes seen upon binding of ubiquitin to ubiquitin-activating enzyme E1. The recognition of E1 by ubiquitin is therefore best explained by conformational selection rather than induced-fit motion.
我们提出了在 2500 巴下基于核 Overhauser 效应的泛素 Q41N 变体的结构测定，其中替代折叠的 N2 态的占有率为 97%。这使我们能够描述泛素的“纯”N2 态的结构。与正常折叠的 N1 态相比，N2 态中β5 链的取向发生了很大的变化，这与泛素与泛素激活酶 E1 结合时所观察到的变化相匹配。因此，泛素与 E1 的识别最好通过构象选择而不是诱导契合运动来解释。
