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The conformational cycle of kinesin
R A Cross1, I Crevel, N J Carter
1Molecular Motors Group, Marie Curie Research Institute, The Chart, Oxted, Surrey, UK. r.cross@mcri.ac.uk
Summary
Kinesin
Area of Science:
- Biochemistry
- Molecular Biology
- Cell Biology
Background:
- Kinesin is a motor protein that transports cargo within cells.
- Its movement relies on a complex stepping mechanism involving conformational changes.
- Understanding this mechanism is crucial for cell biology and disease research.
Purpose of the Study:
- To model the stepping mechanism of kinesin based on existing evidence.
- To elucidate the roles of ATP binding, hydrolysis, and ADP release in kinesin's movement.
- To propose a strain-sensitive model for kinesin detachment.
Main Methods:
- Review of protein chemical evidence.
- Analysis of electron microscopic data.
- Interpretation of transient kinetic studies.
Main Results:
- A model where kinesin heads alternate binding and releasing ADP.
- Microtubule binding triggers ADP release from the trailing head.
- ATP binding and hydrolysis by the trailing head facilitate leading head attachment.
- The leading head's ADP release and pull on the trailing head drive movement.
- A strain-sensitive gate controls ADP trapping and detachment rate.
Conclusions:
- Kinesin's stepping mechanism involves coordinated conformational changes.
- ADP release and ATP hydrolysis are key regulatory steps.
- Strain sensitivity in the molecular gate is a critical feature for kinesin function.