Bidirectional power stroke by ncd kinesin.

Published

Journal Article

Optical trapping experiments reveal details of molecular motor dynamics. In noisy data, temporal structure within the power stroke of motors can be analyzed by ensemble averaging, but this obscures infrequent subcategories of events. We have here developed an analysis method that uses Kalman filtering of measurements, model-based estimation of the power strokes produced by the motor head, and automatic event classification to discriminate between different types of motor events. This method was applied to optical trap measurements of power strokes of the Drosophila kinesin-14 ncd in a three-bead geometry. We found the majority of events to be consistent with the previously discovered minus-end directed power stroke of ncd, occurring with ATP binding. Unexpectedly, 30% of apparent power strokes were plus-directed and 6% of binding events did not terminate in a discernible stroke. Ensemble averaging for each event category revealed that plus- and minus-directed strokes have different size and occur at different instants within the ncd-MT attachment sequence.

Full Text

Duke Authors

Cited Authors

  • Butterfield, AE; Stewart, RJ; Schmidt, CF; Skliar, M

Published Date

  • December 2010

Published In

Volume / Issue

  • 99 / 12

Start / End Page

  • 3905 - 3915

PubMed ID

  • 21156132

Pubmed Central ID

  • 21156132

Electronic International Standard Serial Number (EISSN)

  • 1542-0086

International Standard Serial Number (ISSN)

  • 0006-3495

Digital Object Identifier (DOI)

  • 10.1016/j.bpj.2010.10.045

Language

  • eng