Myosin VI walks "Wiggly" on actin with large and variable tilting
Myosin VI walks "Wiggly" on actin with large and variable tilting
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DOI：
10.1016/j.molcel.2007.10.029
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发表时间：
2007-12-28
期刊：
影响因子：
16
通讯作者：
Goldman, Yale E.
中科院分区：
文献类型：
--
作者：
Sun, Yujie;Schroeder, Harry W., III;Goldman, Yale E.
肌球蛋白VI是一种非传统的运动蛋白，具有不寻常的运动特性，如其运动方向和肌动蛋白上的路径以及相对于其短杠杆臂的大步幅。为了了解这些功能，旋转动力学的杠杆臂进行了研究，通过单分子偏振全内反射荧光（polTIRF）显微镜肌球蛋白VI沿着肌动蛋白的进行性运动。轴向角呈双峰分布，符合手交模型。在离散步骤的杠杆臂角度的变化表明，它表现出大的和可变的倾斜在肌动蛋白的平面和两侧。这些运动意味着，除了以前建议的灵活的尾部域，有一个顺应性的区域之间的电机域和杠杆臂，允许肌球蛋白VI，以适应结合位点的螺旋位置，同时采取可变步长沿着肌动蛋白丝。
Myosin VI is an unconventional motor protein with unusual motility properties such as its direction of motion and path on actin and a large stride relative to its short lever arms. To understand these features, the rotational dynamics of the lever arm were studied by single-molecule polarized total internal reflection fluorescence (polTIRF) microscopy during processive motility of myosin VI along actin. The axial angle is distributed in two peaks, consistent with the hand-over-hand model. The changes in lever arm angles during discrete steps suggest that it exhibits large and variable tilting in the plane of actin and to the sides. These motions imply that, in addition to the previously suggested flexible tail domain, there is a compliant region between the motor domain and lever arm that allows myosin VI to accommodate the helical position of binding sites while taking variable step sizes along the actin filament.