Nucleotide binding and hydrolysis induces a disorder-order transition in the kinesin neck-linker region
Nucleotide binding and hydrolysis induces a disorder-order transition in the kinesin neck-linker region
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DOI：
10.1038/nsmb1109
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发表时间：
2006-07-01
影响因子：
16.8
通讯作者：
Sosa, Hernando
中科院分区：
文献类型：
--
作者：
Asenjo, Ana B.;Weinberg, Yonatan;Sosa, Hernando
驱动蛋白易位被认为是通过运动域中称为颈连接体的区域中的构象变化而发生的。然而，大多数支持这一假设的证据来自无法移动proc的单体结构。为了解决这个问题，我们研究了颈连接器配置微管结合的单体和二聚体驱动蛋白结构，使用单分子荧光偏振显微镜。我们发现颈连接区（i）在不存在核苷酸的情况下和在稳定行走期间是非常移动的，（ii）在AMPPNP或ADP+ AlF 4-的存在下降低移动性并沿着微管轴排列，（iii）在ADP+ AlF 4-的存在下在单体构建体中大部分是有序的，以及（iv）在二聚体构建体中更接近平行于微管轴。这些结果支持提出的颈部连接器的作用，并建议在二聚体的两个电机域之间的协调机制。
Kinesin translocation is thought to occur by a conformational change in a region of the motor domain called the neck linker. However, most evidence supporting this hypothesis comes from monomeric constructs unable to move processively. To address this issue, we investigated the neck-linker configuration on microtubule-bound monomeric and dimeric kinesin constructs using single-molecule fluorescence polarization microscopy. We found that the neck-linker region (i) is very mobile in the absence of nucleotides and during steady walking, (ii) decreases mobility and aligns along the microtubule axis in the presence of AMPPNP or ADP+AlF4-, (iii) is mostly ordered in the monomeric constructs in the presence of ADP+AlF4-, and (iv) is closer to parallel to the microtubule axis in the dimeric constructs. These results support the proposed role of the neck linker and suggest a coordination mechanism between the two motor domains in the dimer.