title: The bipolar assembly domain of the mitotic motor kinesin-5.
abstract: An outstanding unresolved question is how does the mitotic spindle utilize microtubules and mitotic motors to coordinate accurate chromosome segregation during mitosis? This process depends upon the mitotic motor, kinesin-5, whose unique bipolar architecture, with pairs of motor domains lying at opposite ends of a central rod, allows it to crosslink microtubules within the mitotic spindle and to coordinate their relative sliding during spindle assembly, maintenance and elongation. The structural basis of kinesin-5's bipolarity is, however, unknown, as protein asymmetry has so far precluded its crystallization. Here we use electron microscopy of single molecules of kinesin-5 and its subfragments, combined with hydrodynamic analysis plus mass spectrometry, circular dichroism and site-directed spin label electron paramagnetic resonance spectroscopy, to show how a staggered antiparallel coiled-coil 'BASS' (bipolar assembly) domain directs the assembly of four kinesin-5 polypeptides into bipolar minifilaments.
authors.affiliation: Department of Molecular and Cellular Biology, University of California, One Shields Avenue, Davis, California 95616, USA.
authors.forename: Seyda
authors.initials: S
authors.lastname: Acar
authors.forename: David B
authors.initials: DB
authors.lastname: Carlson
authors.forename: Madhu S
authors.initials: MS
authors.lastname: Budamagunta
authors.forename: Vladimir
authors.initials: V
authors.lastname: Yarov-Yarovoy
authors.forename: John J
authors.initials: JJ
authors.lastname: Correia
authors.forename: Milady R
authors.initials: MR
authors.lastname: Niñonuevo
authors.forename: Weitao
authors.initials: W
authors.lastname: Jia
authors.forename: Li
authors.initials: L
authors.lastname: Tao
authors.forename: Julie A
authors.initials: JA
authors.lastname: Leary
authors.forename: John C
authors.initials: JC
authors.lastname: Voss
authors.forename: James E
authors.initials: JE
authors.lastname: Evans
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Scholey
mesh_terms: D000818:Animals; D003545:Cysteine / Q000235:genetics; D029721:Drosophila Proteins / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure; D004331:Drosophila melanogaster / Q000166:cytology* / Q000378:metabolism*; D004578:Electron Spin Resonance Spectroscopy; D057446:Hydrodynamics; D013058:Mass Spectrometry; D008869:Microtubule-Associated Proteins / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure; D008938:Mitosis; D008970:Molecular Weight; D050505:Mutant Proteins / Q000737:chemistry; D009154:Mutation / Q000235:genetics; D053758:Nanoparticles / Q000648:ultrastructure; D063347:Native Polyacrylamide Gel Electrophoresis; D055503:Protein Multimerization; D017434:Protein Structure, Tertiary; D040681:Structural Homology, Protein; D013329:Structure-Activity Relationship
chemical_list: D029721:Drosophila Proteins; C084034:Klp61F protein, Drosophila; D008869:Microtubule-Associated Proteins; D050505:Mutant Proteins; D003545:Cysteine