TY - JOUR
T1 - Stepping and stretching. How kinesin uses internal strain to walk processively
AU - Rosenfeld, Steven S.
AU - Fordyce, Polly M.
AU - Jefferson, Geraldine M.
AU - King, Peter H.
AU - Block, Steven M.
PY - 2003/5/16
Y1 - 2003/5/16
N2 - The ability of kinesin to travel long distances on its microtubule track without dissociating has led to a variety of models to explain how this remarkable degree of processivity is maintained. All of these require that the two motor domains remain enzymatically "out of phase," a behavior that would ensure that, at any given time, one motor is strongly attached to the microtubule. The maintenance of this coordination over many mechanochemical cycles has never been explained, because key steps in the cycle could not be directly observed. We have addressed this issue by applying several novel spectroscopic approaches to monitor motor dissociation, phosphate release, and nucleotide binding during processive movement by a dimeric kinesin construct. Our data argue that the major effect of the internal strain generated when both motor domains of kinesin bind the microtubule is to block ATP from binding to the leading motor. This effect guarantees the two motor domains remain out of phase for many mechanochemical cycles and provides an efficient and adaptable mechanism for the maintenance of processive movement.
AB - The ability of kinesin to travel long distances on its microtubule track without dissociating has led to a variety of models to explain how this remarkable degree of processivity is maintained. All of these require that the two motor domains remain enzymatically "out of phase," a behavior that would ensure that, at any given time, one motor is strongly attached to the microtubule. The maintenance of this coordination over many mechanochemical cycles has never been explained, because key steps in the cycle could not be directly observed. We have addressed this issue by applying several novel spectroscopic approaches to monitor motor dissociation, phosphate release, and nucleotide binding during processive movement by a dimeric kinesin construct. Our data argue that the major effect of the internal strain generated when both motor domains of kinesin bind the microtubule is to block ATP from binding to the leading motor. This effect guarantees the two motor domains remain out of phase for many mechanochemical cycles and provides an efficient and adaptable mechanism for the maintenance of processive movement.
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U2 - 10.1074/jbc.M300849200
DO - 10.1074/jbc.M300849200
M3 - Article
C2 - 12626516
AN - SCOPUS:0038381479
SN - 0021-9258
VL - 278
SP - 18550
EP - 18556
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 20
ER -