Chernyatina Anastasia A, Guzenko Dmytro, Strelkov Sergei V
Laboratory for Biocrystallography, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Belgium.
Laboratory for Biocrystallography, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Belgium.
Curr Opin Cell Biol. 2015 Feb;32:65-72. doi: 10.1016/j.ceb.2014.12.007. Epub 2015 Jan 14.
Intermediate filaments (IFs) result from a key cytoskeletal protein class in metazoan cells, but currently there is no consensus as to their three-dimensional architecture. IF proteins form elongated dimers based on the coiled-coil structure within their central 'rod' domain. Here we focus on the atomic structure of this elementary dimer, elucidated using X-ray crystallography on multiple fragments and electron paramagnetic resonance experiments on spin-labelled vimentin samples. In line with conserved sequence features, the rod of all IF proteins is composed of three coiled-coil segments containing heptad and hendecad repeats and interconnected by linkers. In addition, the next assembly intermediate beyond the dimer, the tetramer, could be modelled. The impact of these structural results towards understanding the assembly mechanism is discussed.
中间丝（IFs）是后生动物细胞中一类关键的细胞骨架蛋白，但目前关于它们的三维结构尚无定论。IF蛋白基于其中心“杆状”结构域内的卷曲螺旋结构形成细长的二聚体。在这里，我们聚焦于这种基本二聚体的原子结构，通过对多个片段进行X射线晶体学分析以及对自旋标记波形蛋白样品进行电子顺磁共振实验来阐明。与保守的序列特征一致，所有IF蛋白的杆状结构由三个包含七肽和十一肽重复序列的卷曲螺旋片段组成，并通过连接子相互连接。此外，还可以构建二聚体之后的下一个组装中间体——四聚体的模型。讨论了这些结构结果对理解组装机制的影响。
