Structure of the complex of a mitotic kinesin with its calcium binding regulator.
Much of the transport, tension, and movement in mitosis depends on kinesins, the ATP-powered microtubule-based motors. We report the crystal structure of a kinesin complex, the mitotic kinesin KCBP bound to its principal regulator KIC. Shown to be a Ca(2+) sensor, KIC works as an allosteric trap. Extensive intermolecular interactions with KIC stabilize kinesin in its ADP-bound conformation. A critical component of the kinesin motile mechanism, called the neck mimic, switches its association from kinesin to KIC, stalling the motor. KIC denies access of the motor to its track by steric interference. Two major features of this regulation, allosteric trapping and steric blocking, are likely to be general for all kinesins.
Department of Biochemistry/Biophysics, University of California, San Francisco, CA 94107, USA.
Maia V
MV
Vinogradova
Galina G
GG
Malanina
Anireddy S N
AS
Reddy
Robert J
RJ
Fletterick
D029681:Arabidopsis Proteins / Q000737:chemistry*; D002135:Calcium-Binding Proteins / Q000737:chemistry*; D002148:Calmodulin-Binding Proteins / Q000737:chemistry*; D018360:Crystallography, X-Ray; D016547:Kinesins / Q000737:chemistry*; D008869:Microtubule-Associated Proteins / Q000737:chemistry*; D008938:Mitosis; D011485:Protein Binding; D011487:Protein Conformation
D029681:Arabidopsis Proteins; D002135:Calcium-Binding Proteins; D002148:Calmodulin-Binding Proteins; C099551:KCBP protein, Arabidopsis; C484060:KIC protein, Arabidopsis; D008869:Microtubule-Associated Proteins; D016547:Kinesins