The dynamics of many macromolecular machines are characterized by chemically mediated structural changes that achieve large-scale functional deployment through local rearrangements of constitutive protein subunits. Motivated by recent high-resolution structural microscopy of a particular class of such machines, contractile injection systems (CISs), we construct a coarse-grained semianalytical model that recapitulates the geometry and bistability of CISs in terms of a minimal set of measurable physical parameters. We use this model to predict the size, shape, and speed of a dynamical actuation front that underlies contraction. Scaling laws for the velocity and physical extension of the contraction front are consistent with our numerical simulations and may be generally applicable to related systems.

中文翻译：

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收缩注射系统的结构动力学


许多大分子机器的动力学特征是化学介导的结构变化，这些变化通过组成型蛋白质亚基的局部重排实现大规模功能部署。受最近对特定类别的此类机器收缩注射系统 （CIS） 的高分辨率结构显微镜的启发，我们构建了一个粗粒度半分析模型，该模型根据一组最小的可测量物理参数概括了 CIs 的几何形状和双稳性。我们使用此模型来预测作为收缩基础的动态驱动前沿的大小、形状和速度。收缩前沿的速度和物理延伸的缩放定律与我们的数值模拟一致，可能普遍适用于相关系统。