title: Intramolecular strain coordinates kinesin stepping behavior along microtubules.
abstract: Kinesin advances 8 nm along a microtubule per ATP hydrolyzed, but the mechanism responsible for coordinating the enzymatic cycles of kinesin's two identical motor domains remains unresolved. Here, we have tested whether such coordination is mediated by intramolecular tension generated by the "neck linkers," mechanical elements that span between the motor domains. When tension is reduced by extending the neck linkers with artificial peptides, the coupling between ATP hydrolysis and forward stepping is impaired and motor's velocity decreases as a consequence. However, speed recovers to nearly normal levels when external tension is applied by an optical trap. Remarkably, external load also induces bidirectional stepping of an immotile kinesin that lacks its mechanical element (neck linker) and fuel (ATP). Our results indicate that the kinesin motor domain senses and responds to strain in a manner that facilitates its plus-end-directed stepping and communication between its two motor domains.
authors.affiliation: Department of Cellular and Molecular Pharmacology and the Howard Hughes Medical Institute, University of California, San Francisco, CA 94158, USA.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Yildiz
authors.forename: Michio
authors.initials: M
authors.lastname: Tomishige
authors.forename: Arne
authors.initials: A
authors.lastname: Gennerich
authors.forename: Ronald D
authors.initials: RD
authors.lastname: Vale
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D054468:Axoneme / Q000378:metabolism; D016547:Kinesins / Q000737:chemistry* / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D009068:Movement; D015202:Protein Engineering; D017434:Protein Structure, Tertiary; D012617:Sea Urchins
chemical_list: D000255:Adenosine Triphosphate; D016547:Kinesins