+Search query
-Structure paper
Title | The kinesin-1 motor protein is regulated by a direct interaction of its head and tail. |
---|---|
Journal, issue, pages | Proc Natl Acad Sci U S A, Vol. 105, Issue 26, Page 8938-8943, Year 2008 |
Publish date | Jul 1, 2008 |
Authors | Kristen A Dietrich / Charles V Sindelar / Paul D Brewer / Kenneth H Downing / Christine R Cremo / Sarah E Rice / |
PubMed Abstract | Kinesin-1 is a molecular motor protein that transports cargo along microtubules. Inside cells, the vast majority of kinesin-1 is regulated to conserve ATP and to ensure its proper intracellular ...Kinesin-1 is a molecular motor protein that transports cargo along microtubules. Inside cells, the vast majority of kinesin-1 is regulated to conserve ATP and to ensure its proper intracellular distribution and coordination with other molecular motors. Regulated kinesin-1 folds in half at a hinge in its coiled-coil stalk. Interactions between coiled-coil regions near the enzymatically active heads at the N terminus and the regulatory tails at the C terminus bring these globular elements in proximity and stabilize the folded conformation. However, it has remained a mystery how kinesin-1's microtubule-stimulated ATPase activity is regulated in this folded conformation. Here, we present evidence for a direct interaction between the kinesin-1 head and tail. We photochemically cross-linked heads and tails and produced an 8-A cryoEM reconstruction of the cross-linked head-tail complex on microtubules. These data demonstrate that a conserved essential regulatory element in the kinesin-1 tail interacts directly and specifically with the enzymatically critical Switch I region of the head. This interaction suggests a mechanism for tail-mediated regulation of the ATPase activity of kinesin-1. In our structure, the tail makes simultaneous contacts with the kinesin-1 head and the microtubule, suggesting the tail may both regulate kinesin-1 in solution and hold it in a paused state with high ADP affinity on microtubules. The interaction of the Switch I region of the kinesin-1 head with the tail is strikingly similar to the interactions of small GTPases with their regulators, indicating that other kinesin motors may share similar regulatory mechanisms. |
External links | Proc Natl Acad Sci U S A / PubMed:18579780 / PubMed Central |
Methods | EM (helical sym.) |
Resolution | 8.0 Å |
Structure data | EMDB-5011: |