Schutt C E, Rozycki M D, Chik J K, Lindberg U
Department of Chemistry, Henry H. Hoyt Laboratory, Princeton University, New Jersey 08544, USA.
Biophys J. 1995 Apr;68(4 Suppl):12S-17S; discussion 17S-18S.
Knowledge of the structure of actin in its various conformational states is important for understanding the diverse motile activities carried out by eukaryotic cells. Profilin:actin crystals provide a unique system for studying conformational states of actin, because they exhibit a high degree of polymorphism in response to environmental conditions while maintaining crystalline order. A preliminary comparison of two states of profilin:beta-actin crystals shows that crystal polymorphism involves movements of actin subdomains at hinge points homologous to those found in hexokinase, a protein whose polypeptide fold is related to actin. The homology of the hinge points in actin to those in hexokinase suggests that actin subdomain movements in profilin:beta-actin crystals have functional significance. We discuss how these movements could be related to structural transitions between states of filamentous actin in muscle contraction.
了解肌动蛋白在其各种构象状态下的结构，对于理解真核细胞进行的多种运动活动至关重要。丝切蛋白：肌动蛋白晶体为研究肌动蛋白的构象状态提供了一个独特的系统，因为它们在保持晶体有序性的同时，会因环境条件而呈现出高度的多态性。对丝切蛋白：β - 肌动蛋白晶体的两种状态进行的初步比较表明，晶体多态性涉及肌动蛋白亚结构域在与己糖激酶中发现的铰链点同源的位置处的移动，己糖激酶是一种多肽折叠与肌动蛋白相关的蛋白质。肌动蛋白中的铰链点与己糖激酶中的铰链点的同源性表明，丝切蛋白：β - 肌动蛋白晶体中肌动蛋白亚结构域的移动具有功能意义。我们讨论了这些移动如何与肌肉收缩中丝状肌动蛋白状态之间的结构转变相关。
