大型GTP酶“动力蛋白”介导各种细胞器的膜的成形和重塑。为此，它主要形成四聚物，后者为随后膜的收缩和切断而聚集成寡聚物。一项新的研究介绍了一种动力蛋白四聚物的晶体结构。通过将这一信息与另外所做的分析相结合，Susanne Eschenburg及同事识别出了动力蛋白二聚物之间的界面，提出了这一蛋白的寡聚怎样导致分子内自抑制相互作用之释放的一个机制。作者所做的突变分析有助于了解先天性肌病“Charcot–Marie–Tooth神经病”和“中央核肌病” (centronuclear myopathy)。

    原文链接：Crystal structure of the dynamin tetramer

    原文摘要：The mechanochemical protein dynamin is the prototype of the dynamin superfamily of large GTPases, which shape and remodel membranes in diverse cellular processes1. Dynamin forms predominantly tetramers in the cytosol, which oligomerize at the neck of clathrin-coated vesicles to mediate constriction and subsequent scission of the membrane. Previous studies have described the architecture of dynamin dimers, but the molecular determinants for dynamin assembly and its regulation have remained unclear. Here we present the crystal structure of the human dynamin tetramer in the nucleotide-free state. Combining structural data with mutational studies, oligomerization measurements and Markov state models of molecular dynamics simulations, we suggest a mechanism by which oligomerization of dynamin is linked to the release of intramolecular autoinhibitory interactions. We elucidate how mutations that interfere with tetramer formation and autoinhibition can lead to the congenital muscle disorders Charcot–Marie–Tooth neuropathy and centronuclear myopathy, respectively. Notably, the bent shape of the tetramer explains how dynamin assembles into a right-handed helical oligomer of defined diameter, which has direct implications for its function in membrane constriction.