Kinesins perform mechanical work to power a variety of cellular functions, from mitosis to organelle transport. Distinct functions shape distinct enzymologies, and this is illustrated by comparing kinesin-1, a highly processive transport motor that can work alone, to Eg5, a minimally processive mitotic motor that works in large ensembles. Although crystallographic models for both motors reveal similar structures for the domains involved in mechanochemical transductionâ€"including switch-1 and the neck linkerâ€"how movement of these two domains is coordinated through the ATPase cycle remains unknown. We have addressed this issue by using a novel combination of transient kinetics and time-resolved fluorescence, which we refer to as â€œstructural kinetics,â€to map the timing of structural changes in the switch-1 loop and neck linker. We find that differences between the structural kinetics of Eg5 and kinesin-1 yield insights into how these two motors adapt their enzymologies for their distinct functions.
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - 1 Dec 2015|
- Fluorescence resonance energy transfer
- Molecular motor
- Time-resolved fluorescence
- Transient kinetics