Doering C, Ermentrout B, Oster G
Center for Nonlinear Studies, Los Alamos National Laboratory, New Mexico 87545, USA.
Biophys J. 1995 Dec;69(6):2256-67. doi: 10.1016/S0006-3495(95)80096-2.
Many molecular motors move unidirectionally along a DNA strand powered by nucleotide hydrolysis. These motors are multimeric ATPases with more than one hydrolysis site. We present here a model for how these motors generate the requisite force to process along their DNA track. This novel mechanism for force generation is based on a fluctuating electrostatic field driven by nucleotide hydrolysis. We apply the principle to explain the motion of certain DNA helicases and the portal protein, the motor that bacteriophages use to pump the genome into their capsids. The motor can reverse its direction without reversing the polarity of its electrostatic field, that is, without major structural modifications of the protein. We also show that the motor can be driven by an ion gradient; thus the mechanism may apply as well to the bacterial flagellar motor and to ATP synthase.
许多分子马达在由核苷酸水解提供动力的情况下，沿着DNA链单向移动。这些马达是具有多个水解位点的多聚体ATP酶。我们在此提出一个模型，以解释这些马达如何产生沿着其DNA轨道前进所需的力。这种产生力的新机制基于由核苷酸水解驱动的波动静电场。我们应用这一原理来解释某些DNA解旋酶和门户蛋白的运动，门户蛋白是噬菌体用于将基因组泵入其衣壳的马达。该马达可以在不改变其静电场极性的情况下反转其方向，也就是说，无需对蛋白质进行重大结构修饰。我们还表明，该马达可以由离子梯度驱动；因此，该机制也可能适用于细菌鞭毛马达和ATP合酶。
