title: ESR reveals the mobility of the neck linker in dimeric kinesin.
abstract: Conventional kinesin is a highly processive motor that converts the chemical energy of ATP hydrolysis into the unidirectional motility along microtubules. The processivity is thought to depend on the coordination between ATPase cycles of two motor domains and their neck linkers. Here we have used site-directed spin labeling electron spin resonance (SDSL-ESR) to determine the conformation of the neck linker in kinesin dimer in the presence and absence of microtubules. The spectra show that the neck linkers co-exist in both docked and disordered conformations, which is consistent with the results of monomeric kinesin. In all nucleotide states, however, the neck linkers are well ordered when dimeric kinesin is bound to the microtubule. This result suggests that the orientation of each neck linker that is fixed rigidly controls the kinesin motion along microtubule tracks.
authors.affiliation: Department of Biology, Graduate School of Science, Osaka University, Toyonaka, 560-0043 Osaka, Japan. sugata3@bio.sci.osaka-u.ac.jp
authors.forename: Kazunori
authors.initials: K
authors.lastname: Sugata
authors.forename: Motoyoshi
authors.initials: M
authors.lastname: Nakamura
authors.forename: Shoji
authors.initials: S
authors.lastname: Ueki
authors.forename: Peter G
authors.initials: PG
authors.lastname: Fajer
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Arata
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D019281:Dimerization; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D006868:Hydrolysis; D016547:Kinesins / Q000737:chemistry*; D051379:Mice; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D013997:Time Factors
chemical_list: D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; D016547:Kinesins