Kull F Jon, Endow Sharyn A
Department of Chemistry, Dartmouth College, Hanover, NH 03755, USA.
Trends Biochem Sci. 2004 Mar;29(3):103-6. doi: 10.1016/j.tibs.2004.01.001.
The mechanism by which motor proteins hydrolyze ATP and move along cytoskeletal filaments is still unknown. One approach to deciphering the mechanism is to correlate steps of ATP hydrolysis with structural states of the motors to determine the changes the motors undergo during the hydrolysis cycle. Unfortunately, available crystal structures represent only a few steps of the cycle and obtaining atomic structures that represent the motors bound to their filament has been difficult. Now, two new myosin crystal structures have been reported that show features expected for myosin motors bound in rigor to actin. The two new structures show changes at both the actin-binding surface and the active site that have not been observed previously.
驱动蛋白水解ATP并沿细胞骨架丝移动的机制仍然未知。一种破解该机制的方法是将ATP水解步骤与驱动蛋白的结构状态相关联，以确定驱动蛋白在水解循环过程中所经历的变化。不幸的是，现有的晶体结构仅代表该循环的少数几个步骤，而获得代表与细丝结合的驱动蛋白的原子结构一直很困难。现在，有两篇关于肌球蛋白的新晶体结构的报道，它们展示了预期的肌球蛋白马达与肌动蛋白紧密结合的特征。这两个新结构显示出在肌动蛋白结合表面和活性位点都有以前未观察到的变化。
