Modular Aspects of Kinesin Force Generation Machinery

摘要: The motor head of kinesin carries out microtubule binding, ATP hydrolysis, and force generation. Despite a high level sequence structural conservation, subtle variations in subdomains the determine family-specific properties. In particular, both Kinesin-1 (Kin-1) Kinesin-5 (Kin-5) walk processively to plus-end, yet show distinct motility characteristics suitable for their functions. We studied chimeric Kin-1/Kin-5 constructs with combination single molecule assays molecular dynamics simulations demonstrate that Kin-5 possesses force-generating element similar Kin-1, i.e., cover-neck bundle. Furthermore, neck linker makes additional contacts core via loop L13, which putatively compensates shorter bundle Kin-5. Our results indicate Kin-1 is mechanically optimized individual cargo transport, whereas does not necessarily maximize its mechanical performance. Its biochemical rates enhanced sensitivity may instead be beneficial operation group motors. Such would strategy achieving diversity conserved head.