Alternate fast and slow stepping of a heterodimeric kinesin molecule

A conventional kinesin molecule travels continuously along a microtubule in discrete 8-nm steps. This processive movement is generally explained by models in which the two identical heads of a kinesin move in a 'hand-over-hand' manner. Here, we show that a single heterodimeric kinesin molecule (in which one of the two heads is mutated in a nucleotide-binding site) exhibits fast and slow (with the dwell time at least 10 times longer than that of the fast step) 8-nm steps alternately, presumably corresponding to the displacement by the wild-type and mutant heads, respectively. Our results provide the first direct evidence for models in which the roles of the two heads alternate every 8-nm step.

[1]  S. Block,et al.  Versatile optical traps with feedback control. , 1998, Methods in enzymology.

[2]  L. Goldstein,et al.  Bead movement by single kinesin molecules studied with optical tweezers , 1990, Nature.

[3]  T. Yanagida,et al.  Kinetics of force generation by single kinesin molecules activated by laser photolysis of caged ATP. , 1997, Proceedings of the National Academy of Sciences of the United States of America.

[4]  Christoph F. Schmidt,et al.  Direct observation of kinesin stepping by optical trapping interferometry , 1993, Nature.

[5]  Yale E. Goldman,et al.  Three-dimensional structural dynamics of myosin V by single-molecule fluorescence polarization , 2003, Nature.

[6]  T. Yanagida,et al.  Mechanics of single kinesin molecules measured by optical trapping nanometry. , 1997, Biophysical journal.

[7]  E. Taylor,et al.  Interacting Head Mechanism of Microtubule-Kinesin ATPase* , 1997, The Journal of Biological Chemistry.

[8]  K. Hirose,et al.  The conformational cycle of kinesin. , 2000, Philosophical transactions of the Royal Society of London. Series B, Biological sciences.

[9]  Steven M. Block,et al.  Force and velocity measured for single kinesin molecules , 1994, Cell.

[10]  J. Gelles,et al.  Distinguishing Inchworm and Hand-Over-Hand Processive Kinesin Movement by Neck Rotation Measurements , 2002, Science.

[11]  Steven M. Block,et al.  Analysis of high resolution recordings of motor movement. , 1995, Biophysical journal.

[12]  Toshio Yanagida,et al.  Substeps within the 8-nm step of the ATPase cycle of single kinesin molecules , 2001, Nature Cell Biology.

[13]  R. Vale,et al.  Switches, latches, and amplifiers: common themes of G proteins and molecular motors , 1996, The Journal of cell biology.

[14]  D. Hackney,et al.  Evidence for alternating head catalysis by kinesin during microtubule-stimulated ATP hydrolysis. , 1994, Proceedings of the National Academy of Sciences of the United States of America.

[15]  Paul R. Selvin,et al.  Myosin V Walks Hand-Over-Hand: Single Fluorophore Imaging with 1.5-nm Localization , 2003, Science.

[16]  K. Hirose,et al.  Coordination of kinesin's two heads studied with mutant heterodimers , 2002, Proceedings of the National Academy of Sciences of the United States of America.

[17]  J. Howard,et al.  The mechanics of force generation by kinesin. , 1995, Biophysical journal.

[18]  R. Vale,et al.  The way things move: looking under the hood of molecular motor proteins. , 2000, Science.