Structural Biology of Human Dynamin

动力蛋白是一种由五个结构域组成的大型延伸蛋白。我们最近确定了人类动力蛋白1衍生的最小GTPase- ged（“GTPase效应域”）融合蛋白的2.0埃分辨率晶体结构。这种融合蛋白在过渡态模拟gdp -氟化铝存在下二聚化。该结构揭示了动力蛋白的催化机制，并解释了组装刺激GTP水解是如何通过G结构域二聚化实现的。特别有趣的是，在活性位点发现了一个钠离子，这表明动力蛋白使用一个阳离子来补偿在过渡状态中形成的负离子，并为以前无法暗示更常见的精氨酸手指提供了一个基本原理。这种融合区域的结构使我们能够为动力蛋白催化的膜裂变过程中二聚化的作用提供一个模型。

Dynamin is a large, extended protein consisting of five domains. We have recently determined the 2.0 Angstrom resolution crystal structure of a human dynamin 1-derived minimal GTPase-GED (for "GTPase effector domain") fusion protein. This fusion protein dimerizes in the presence of the transition state mimic GDP-aluminum fluoride. The structure reveals dynamin's catalytic machinery and explains how assembly-stimulated GTP hydrolysis is achieved through G domain dimerization. Particularly intriguing was the identification of a sodium ion in the active site, suggesting that dynamin uses a cation to compensate for the developing negative in the transition state and providing a rationale for the inability to previously implicate a more-usual arginine finger. The structure of this fusion domain allows us to provide a model for the role of dimerization during dynamin-catalyzed membrane fission.