Kikkawa Masahide
Graduate School of Science, Kyoto University, Oiwake, Kita-shirakawa, Sakyo-ku, Kyoto, 606-8502, Japan.
Trends Cell Biol. 2008 Mar;18(3):128-35. doi: 10.1016/j.tcb.2008.01.002. Epub 2008 Feb 15.
Kinesins are microtubule-based motors that are important for various intracellular transport processes. To understand the mechanism of kinesin movement, X-ray crystallography has been used to study the atomic structures of kinesin. However, as crystal structures of kinesin alone accumulate, it is becoming clear that kinesin structures should also be investigated with the microtubule to understand the contribution of the microtubule track to the nucleotide-induced conformational changes of kinesin. Recently, several high-resolution structures of kinesin with microtubules were obtained using cryo-electron microscopy. Comparison with X-ray crystallographic structures revealed the importance of the microtubule in determining the conformation of kinesin. Together with recent biophysical data, we describe different structural models of processive kinesin movement and provide a framework for future experiments.
驱动蛋白是基于微管的马达蛋白，对各种细胞内运输过程都很重要。为了理解驱动蛋白的运动机制，人们利用X射线晶体学来研究驱动蛋白的原子结构。然而，随着单独的驱动蛋白晶体结构不断积累，越来越清楚的是，还应该结合微管来研究驱动蛋白的结构，以了解微管轨道对核苷酸诱导的驱动蛋白构象变化的作用。最近，利用冷冻电子显微镜获得了驱动蛋白与微管的几个高分辨率结构。与X射线晶体学结构的比较揭示了微管在确定驱动蛋白构象方面的重要性。结合最近的生物物理数据，我们描述了持续驱动蛋白运动的不同结构模型，并为未来的实验提供了一个框架。
