Actin crystal dynamics: structural implications for F-actin nucleation, polymerization, and branching mediated by the anti-parallel dimer
Actin crystal dynamics: structural implications for F-actin nucleation, polymerization, and branching mediated by the anti-parallel dimer
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DOI：
10.1016/j.jsb.2003.12.006
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发表时间：
2004-06-01
影响因子：
3
通讯作者：
McKenna, R
中科院分区：
文献类型：
--
作者：
Reutzel, R;Yoshioka, C;McKenna, R
肌动蛋白丝成核、聚合和分支是许多生物体中细胞运动、细胞形状和细胞内细胞器运动的重要步骤。先前的生物化学数据表明，一个反平行肌动蛋白二聚体可以将自己纳入生长的丝状肌动蛋白（F-肌动蛋白），并在分支的作用。此外，人们普遍认为成核是由肌动蛋白三聚体复合物产生的。本文报道了P4（3）2（1）2和P4（3）两个四元晶系中肌动蛋白二聚体和三聚体的结构。这两个晶体系统都是由先前报道的斜方晶系P2（1）2（1）2（1）的诱导缩合转变形成的。三种晶体系统之间的比较表明肌动蛋白-肌动蛋白相互作用的动力学和灵活性。在三种晶体系统之间观察到的二聚体和三聚体肌动蛋白重排可以提供对在体内肌动蛋白-肌动蛋白相互作用的洞察，所述相互作用发生在F-肌动蛋白的成核、聚合和分支过程中。(C)2003年爱思唯尔公司All rights reserved.
Actin filament nucleation, polymerization, and branching are crucial steps in many forms of cell motility, cell shape, and intracellular organelle movements in a wide range of organisms. Previous biochemical data suggests that an anti-parallel actin dimer can incorporate itself into growing filamentous actin (F-actin) and has a role in branching. Furthermore, it is a widespread belief that nucleation is spawned from an actin trimer complex. Here we present the structures of actin dimers and trimers in two tetragonal crystal systems P4(3)2(1)2 and P4(3). Both crystal systems formed by an induced condensation transformation of a previously reported orthorhombic crystal system P2(1)2(1)2(1). Comparison between the three crystal systems demonstrates the dynamics and flexibility of actin-actin interactions. The dimer and trimer actin rearrangements observed between the three crystal systems may provide insight to in vivo actin-actin interactions that occur during the nucleation, polymerization, and branching of F-actin. (C) 2003 Elsevier Inc. All rights reserved.