.png){kind=icon}
返回
Why kinesin is so processive
.png){kind=icon}
OA
AI
DOI：10.1073/pnas.0808396106.png)
.png){kind=icon}
.png){kind=icon}
分享.png){kind=icon}
收藏
摘要
En 中文
Kinesin I can walk on a microtubule for distances as long as several micrometers. However, it is still unclear how this molecular motor can remain attached to the microtubule through the hundreds of mechanochemical cycles necessary to achieve this remarkable degree of processivity. We have addressed this issue by applying ensemble and single-molecule fluorescence methods to study the process of kinesin stepping, and our results lead to 4 conclusions. First, under physiologic conditions, approximate to 75% of processively moving kinesin molecules are attached to the microtubule via both heads, and in this conformation, they are resistant to dissociation. Second, the remaining 25% of kinesin molecules, which are in an ATP waiting state'' and are strongly attached to the microtubule via only one head, are intermittently in a conformation that cannot bind ATP and therefore are resistant to nucleotide-induced dissociation. Third, the forward step in the kinesin ATPase cycle is very fast, accounting for <5% of the total cycle time, which ensures that the lifetime of this ATP waiting state is relatively short. Finally, by combining nanometer-level single-molecule fluorescence localization with higher ATP concentrations than used previously, we have determined that in this ATP waiting state, the ADP-containing head of kinesin is located 8 nm behind the attached head, in a location where it can interact with the microtubule lattice. These 4 features reduce the likelihood that a kinesin I motor will dissociate and contribute to making this motor so highly processive.
Keyword:
fluorescence
motility
gating
fluorescence imaging with 1-nm accuracy
processivity
AI总结
对已上传原文的论文进行重点信息的提取，主要内容包括：简要概述、研究摘要、背景介绍、关键亮点、图文解析、展望与总结。
期刊
P
IF:
9.1
论文数:
10.8W
被引数:
73.5W
机构
引用论文
.png){kind=icon}
分享收藏Bacterial Contamination of Hemodialysis Center Water and Dialysate: Are Current Assays Adequate?
PREAI
分享收藏
查看更多内容