TY - JOUR
T1 - A universal pathway for kinesin stepping
AU - Clancy, Bason E.
AU - Behnke-Parks, William M.
AU - Andreasson, Johan O.L.
AU - Rosenfeld, Steven S.
AU - Block, Steven M.
N1 - Funding Information:
S.M.B. acknowledges support from grant GM51453, and S.S.R. acknowledges support from grant AR048565 from the US National Institutes of Health.
PY - 2011/9
Y1 - 2011/9
N2 - Kinesin-1 is an ATP-driven, processive motor that transports cargo along microtubules in a tightly regulated stepping cycle. Efficient gating mechanisms ensure that the sequence of kinetic events proceeds in the proper order, generating a large number of successive reaction cycles. To study gating, we created two mutant constructs with extended neck-linkers and measured their properties using single-molecule optical trapping and ensemble fluorescence techniques. Owing to a reduction in the inter-head tension, the constructs access an otherwise rarely populated conformational state in which both motor heads remain bound to the microtubule. ATP-dependent, processive backstepping and futile hydrolysis were observed under moderate hindering loads. On the basis of measurements, we formulated a comprehensive model for kinesin motion that incorporates reaction pathways for both forward and backward stepping. In addition to inter-head tension, we found that neck-linker orientation is also responsible for ensuring gating in kinesin.
AB - Kinesin-1 is an ATP-driven, processive motor that transports cargo along microtubules in a tightly regulated stepping cycle. Efficient gating mechanisms ensure that the sequence of kinetic events proceeds in the proper order, generating a large number of successive reaction cycles. To study gating, we created two mutant constructs with extended neck-linkers and measured their properties using single-molecule optical trapping and ensemble fluorescence techniques. Owing to a reduction in the inter-head tension, the constructs access an otherwise rarely populated conformational state in which both motor heads remain bound to the microtubule. ATP-dependent, processive backstepping and futile hydrolysis were observed under moderate hindering loads. On the basis of measurements, we formulated a comprehensive model for kinesin motion that incorporates reaction pathways for both forward and backward stepping. In addition to inter-head tension, we found that neck-linker orientation is also responsible for ensuring gating in kinesin.
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U2 - 10.1038/nsmb.2104
DO - 10.1038/nsmb.2104
M3 - Article
C2 - 21841789
AN - SCOPUS:80052450227
SN - 1545-9993
VL - 18
SP - 1020
EP - 1027
JO - Nature Structural and Molecular Biology
JF - Nature Structural and Molecular Biology
IS - 9
ER -