Howard J
Department of Physiology and Biophysics, University of Washington, Seattle 98195-7290, USA.
Nature. 1997 Oct 9;389(6651):561-7. doi: 10.1038/39247.
Molecular motors are protein machines whose directed movement along cytoskeletal filaments is driven by ATP hydrolysis. Eukaryotic cells contain motors that help to transport organelles to their correct cellular locations and to establish and alter cellular morphology during cell locomotion and division. The best-studied motors, myosin from skeletal muscle and conventional kinesin from brain, are remarkably similar in structure, yet have very different functions. These differences can be understood in terms of the 'duty ratio', the fraction of the time that a motor is attached to its filament. Differences in duty ratio can explain the diversity of structures, speeds and oligomerization states of members of the large kinesin, myosin and dynein families of motors.
分子马达是一种蛋白质机器，其沿细胞骨架细丝的定向运动由ATP水解驱动。真核细胞含有一些马达，这些马达有助于将细胞器运输到其在细胞内的正确位置，并在细胞运动和分裂过程中建立和改变细胞形态。研究得最透彻的马达，即骨骼肌中的肌球蛋白和脑中的传统驱动蛋白，在结构上非常相似，但功能却大不相同。这些差异可以用“占空比”来解释，即马达附着在细丝上的时间比例。占空比的差异可以解释大型驱动蛋白、肌球蛋白和动力蛋白家族成员在结构、速度和寡聚化状态上的多样性。
