Holmes K C, Goody R S
Adv Exp Med Biol. 1984;170:373-84. doi: 10.1007/978-1-4684-4703-3_34.
Evidence from sequence studies and from proteolysis suggests that S1 consists of three domains. Cross-linking studies show that one S1 can bind to two actin monomers which may lie in different strands of the actin long helix. The S1-actin interaction comprises two states "weak" and "strong". We suggest there are distinct hinged binding sites, "weak" and "rigor", of which only the rigor site is sensitive to tropomyosin control. If one takes the weak binding domain to be a "nose-cone" which is attached to the rest of the S1 by a flexible covalent hinge allowing the rigor link to be formed independently a number of structural phenomena observed in fibres may be explained.
来自序列研究和蛋白水解的证据表明，S1由三个结构域组成。交联研究表明，一个S1可以结合两个肌动蛋白单体，这两个单体可能位于肌动蛋白长螺旋的不同链中。S1与肌动蛋白的相互作用包括“弱”和“强”两种状态。我们认为存在不同的铰链结合位点，即“弱”位点和“强直”位点，其中只有强直位点对原肌球蛋白的控制敏感。如果将弱结合结构域视为一个“鼻锥”，它通过一个柔性共价铰链连接到S1的其余部分，使得强直连接能够独立形成，那么在纤维中观察到的许多结构现象就可以得到解释。
