title: Structural Basis of Backwards Motion in Kinesin-1-Kinesin-14 Chimera: Implication for Kinesin-14 Motility.
abstract: Kinesin-14 is a unique minus-end-directed microtubule-based motor. A swinging motion of a class-specific N-terminal neck helix has been proposed to produce minus-end directionality. However, it is unclear how swinging of the neck helix is driven by ATP hydrolysis utilizing the highly conserved catalytic core among all kinesins. Here, using a motility assay, we show that in addition to the neck helix, the conserved five residues at the C-terminal region in kinesin-14, namely the neck mimic, are necessary to give kinesin-1 an ability to reverse its directionality toward the minus end of microtubules. Our structural analyses further demonstrate that the C-terminal neck mimic, in cooperation with conformational changes in the catalytic core during ATP binding, forms a kinesin-14 bundle with the N-terminal neck helix to swing toward the minus end of microtubules. Thus, the neck mimic plays a crucial role in coupling the chemical ATPase reaction with the mechanical cycle to produce the minus-end-directed motility of kinesin-14.
authors.affiliation: Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Tokyo 153-8902, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Yamagishi
authors.affiliation: RIKEN Center for Life Science Technologies, Tsurumi-ku, Yokohama 230-0045, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Shigematsu
authors.affiliation: RIKEN Center for Life Science Technologies, Tsurumi-ku, Yokohama 230-0045, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yokoyama
authors.affiliation: Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan; CREST, JST, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Masahide
authors.initials: M
authors.lastname: Kikkawa
authors.affiliation: Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Tokyo 153-8902, Japan.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Sugawa
authors.affiliation: RIKEN Center for Life Science Technologies, Tsurumi-ku, Yokohama 230-0045, Japan.
authors.forename: Mari
authors.initials: M
authors.lastname: Aoki
authors.affiliation: RIKEN Center for Life Science Technologies, Tsurumi-ku, Yokohama 230-0045, Japan.
authors.forename: Mikako
authors.initials: M
authors.lastname: Shirouzu
authors.affiliation: Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Tokyo 153-8902, Japan. Electronic address: yajima@bio.c.u-tokyo.ac.jp.
authors.forename: Junichiro
authors.initials: J
authors.lastname: Yajima
authors.affiliation: RIKEN Center for Life Science Technologies, Tsurumi-ku, Yokohama 230-0045, Japan. Electronic address: ryo.nitta@riken.jp.
authors.forename: Ryo
authors.initials: R
authors.lastname: Nitta
mesh_terms: D000244:Adenosine Diphosphate / Q000737:chemistry* / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000737:chemistry* / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D029721:Drosophila Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D004331:Drosophila melanogaster / Q000737:chemistry / Q000378:metabolism; D015870:Gene Expression; D016547:Kinesins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism* / Q000648:ultrastructure; D062105:Molecular Docking Simulation; D056004:Molecular Dynamics Simulation; D009038:Motion; D011485:Protein Binding; D000072756:Protein Conformation, alpha-Helical; D000072757:Protein Conformation, beta-Strand; D054730:Protein Interaction Domains and Motifs; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D013816:Thermodynamics
chemical_list: D029721:Drosophila Proteins; D020033:Protein Isoforms; D011993:Recombinant Fusion Proteins; C066696:ncd protein, Drosophila; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; C000612996:KIF5C protein, rat; D016547:Kinesins