Department of Biochemistry, B400 Beckman Center, Stanford University School of Medicine, Stanford, California 94305-5307, USA.
Nat Rev Mol Cell Biol. 2010 Feb;11(2):128-37. doi: 10.1038/nrm2833.
The swinging crossbridge hypothesis states that energy from ATP hydrolysis is transduced to mechanical movement of the myosin head while bound to actin. The light chain-binding region of myosin is thought to act as a lever arm that amplifies movements near the catalytic site. This model has been challenged by findings that myosin VI takes larger steps along actin filaments than early interpretations of its structure seem to allow. We now know that myosin VI does indeed operate by an unusual approximately 180 degrees lever arm swing and achieves its large step size using special structural features in its tail domain.
摆动横桥假说指出，当肌球蛋白头部与肌动蛋白结合时，ATP 水解产生的能量被转化为肌球蛋白头部的机械运动。肌球蛋白的轻链结合区域被认为是一个杠杆臂，可放大靠近催化位点的运动。这一模型受到了挑战，因为发现肌球蛋白 VI 沿着肌动蛋白丝的步幅比其早期结构解释似乎允许的要大。我们现在知道，肌球蛋白 VI 确实通过一个不寻常的约 180 度的杠杆臂摆动来运作，并利用其尾部结构域中的特殊结构特征来实现其大步幅。
