Sack S, Müller J, Marx A, Thormählen M, Mandelkow E M, Brady S T, Mandelkow E
Max-Planck-Unit for Structural Molecular Biology, c/o DESY, Notkestrasse 85, D-22607 Hamburg, Germany.
Biochemistry. 1997 Dec 23;36(51):16155-65. doi: 10.1021/bi9722498.
We have determined the X-ray structure of rat kinesin head and neck domains. The folding of the core motor domain resembles that of human kinesin reported recently [Kull, F. J., et al. (1996) Nature 380, 550-554]. Novel features of the structure include the N-terminal region, folded as a beta-strand, and the C-terminal transition from the motor to the rod domain, folded as two beta-strands plus an alpha-helix. This helix is the beginning of kinesin's neck responsible for dimerization of the motor complex and for force transduction. Although the folding of the motor domain core is similar to that of a domain of myosin (an actin-dependent motor), the position and angle of kinesin's neck are very different from those of myosin's stalk, suggesting that the two motors have different mechanisms of force transduction. The N- and C-terminal ends of the core motor, thought to be responsible for the directionality of the motors [Case, R. B., et al. (1997) Cell 90, 959-966], take the form of beta-strands attached to the central beta-sheet of the structure.
我们已经确定了大鼠驱动蛋白头部和颈部结构域的X射线结构。核心运动结构域的折叠方式与最近报道的人类驱动蛋白相似[库尔，F.J.等人（1996年）《自然》380卷，550 - 554页]。该结构的新特征包括折叠成β链的N端区域，以及从运动结构域到杆状结构域的C端过渡区，其折叠方式为两条β链加一个α螺旋。这个螺旋是驱动蛋白颈部的起始部分，负责运动复合体的二聚化和力的传导。虽然运动结构域核心的折叠方式与肌球蛋白（一种依赖肌动蛋白的运动蛋白）的一个结构域相似，但驱动蛋白颈部的位置和角度与肌球蛋白的柄部非常不同，这表明这两种运动蛋白具有不同的力传导机制。核心运动结构域的N端和C端，被认为负责运动蛋白的方向性[凯斯，R.B.等人（1997年）《细胞》90卷，959 - 966页]，采取β链的形式附着在结构的中央β片层上。
