title: The highly processive kinesin-8, Kip3, switches microtubule protofilaments with a bias toward the left.
abstract: Kinesin-1 motor proteins walk parallel to the protofilament axes of microtubules as they step from one tubulin dimer to the next. Is protofilament tracking an inherent property of processive kinesin motors, like kinesin-1, and what are the structural determinants underlying protofilament tracking? To address these questions, we investigated the tracking properties of the processive kinesin-8, Kip3. Using in vitro gliding motility assays, we found that Kip3 rotates microtubules counterclockwise around their longitudinal axes with periodicities of ∼1 μm. These rotations indicate that the motors switch protofilaments with a bias toward the left. Molecular modeling suggests 1), that the protofilament switching may be due to kinesin-8 having a longer neck linker than kinesin-1, and 2), that the leftward bias is due the asymmetric geometry of the motor neck linker complex.
authors: Volker
authors: V
authors: Bormuth
authors: Bert
authors: B
authors: Nitzsche
authors: Felix
authors: F
authors: Ruhnow
authors: Aniruddha
authors: A
authors: Mitra
authors: Marko
authors: M
authors: Storch
authors: Burkhard
authors: B
authors: Rammner
authors: Jonathon
authors: J
authors: Howard
authors: Stefan
authors: S
authors: Diez
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D016547:Kinesins / Q000737:chemistry*; D008856:Microscopy, Fluorescence; D008858:Microscopy, Phase-Contrast; D008870:Microtubules / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D008969:Molecular Sequence Data; D009038:Motion; D011487:Protein Conformation; D045663:Quantum Dots; D014404:Tubulin / Q000737:chemistry*
chemical_list: D014404:Tubulin; D016547:Kinesins