Examining kinesin processivity within a general gating framework
- Stanford University, United States
- Pennsylvania State University, United States
- Howard Hughes Medical Institute, Johns Hopkins University, United States
Abstract
Kinesin-1 is a dimeric motor that transports cargo along microtubules, taking 8.2-nm steps in a hand-over-hand fashion. The ATP hydrolysis cycles of its two heads are maintained out of phase by a series of gating mechanisms, which lead to processive runs averaging ~1 μm. A key structural element for inter-head coordination is the neck linker (NL), which connects the heads to the stalk. To examine the role of the NL in regulating stepping, we investigated NL mutants of various lengths using single-molecule optical trapping and bulk fluorescence approaches in the context of a general framework for gating. Our results show that, although inter-head tension enhances motor velocity, it is crucial neither for inter-head coordination nor for rapid rear-head release. Furthermore, cysteine-light mutants do not produce wild-type motility under load. We conclude that kinesin-1 is primarily front-head gated, and that NL length is tuned to enhance unidirectional processivity and velocity.
Article and author information
Author details
Reviewing Editor
- Anna Akhmanova, Utrecht University, Netherlands
Version history
- Received: March 10, 2015
- Accepted: April 21, 2015
- Accepted Manuscript published: April 22, 2015 (version 1)
- Version of Record published: June 3, 2015 (version 2)
Copyright
© 2015, Andreasson et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Examining kinesin processivity within a general gating framework
eLife 4:e07403.
https://doi.org/10.7554/eLife.07403
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