title: Mechanical amplification mechanism of kinesin's β-domain.
abstract: Conventional kinesin's force generation process always takes place on the leading head and the generated force is transmitted to the trailing head through two neck linkers. To guarantee a strong force to be transmitted to the trailing head so that it can be detached from microtubule surface, the neck linker of the leading head must have a large enough forward displacement, which is proposed to be achieved by the amplifying function of the β-domain. However, the experimental result shows that the forward displacement of the β-domain itself appears too small. To elucidate the function of the β-domain, we make a detailed analysis of the mechanical relationship between the two motor heads and, based on the results of molecular dynamics simulation and mechanical analysis, we calculate the forward displacement of the neck linker of the leading head during the ATP binding induced motor head rotation. We show that β-domain achieves its amplifying function together with β0, so that neck linker can have a forward displacement during motor head rotation. This displacement of neck linker is large enough to cause detachment of the trailing head. Based on these results, a possible initiation mechanism of neck linker docking is proposed.
authors.affiliation: College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875, China.
authors.forename: Yi-Zhao
authors.initials: YZ
authors.lastname: Geng
authors.affiliation: Institute of Biophysics, Hebei University of Technology, Tianjin 300401, China.
authors.forename: Shu-Xia
authors.initials: SX
authors.lastname: Liu
authors.affiliation: Institute of Biophysics, Hebei University of Technology, Tianjin 300401, China. Electronic address: jiqingch@hebut.edu.cn.
authors.forename: Qing
authors.initials: Q
authors.lastname: Ji
authors.affiliation: College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875, China; Beijing Radiation Center, Beijing 100875, China. Electronic address: yansw@bnu.edu.cn.
authors.forename: Shiwei
authors.initials: S
authors.lastname: Yan
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D016547:Kinesins / Q000737:chemistry* / Q000378:metabolism*; D055595:Mechanical Phenomena; D056004:Molecular Dynamics Simulation; D017434:Protein Structure, Tertiary; D012399:Rotation
chemical_list: D000255:Adenosine Triphosphate; D016547:Kinesins
keywords: -Domain; Amplification mechanism; Kinesin; Neck linker