Alternative mechanochemische Reaktionszyklen prozessiver Kinesine

• Applicant: Dr. Tim Scholz
• Subject Area: Cell Biology
• Term: from 2006 to 2010
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 14023866

The mechanochemical pathway of processive kinesin is still controversial in terms of both the relevant intermediates and their sequence. Two models have been proposed that differ in two characteristic intermediates due to the assumptions made about timing of phosphate release from the trailing head versus ATP binding to the leading head. The aim of the present project is to determine which of the two pathways is taken by individual kinesin molecules during processive stepping along microtubules. Ensemble kinetics suggest that specifically labelled kinesins show characteristic changes in fluorescence intensities in one of the alternative pathways. This will be used to analyse which path is taken in consecutive steps, and whether pathway-selection is affected by external conditions like external load. The reverse directed nonclaret disjunctional protein (Ned), a non-processive member of the kinesin family, will be analysed using the same approach. This is expected to reveal differences in the mechanochemical cycle of processive and non-processive kinesins. In collaboration with WP1-Manstein and WP8-Tsiavaliaris, we will address the structural basis of reverse directionality by the rational design of a processive, backwards-moving kinesin.

• DFG Programme: Research Units
• Subproject of: FOR 629: Molecular Mechanisms of Cell Motility