A de novo designed coiled coil-based switch regulates the microtubule motor kinesin-1

Abstract

Many enzymes are allosterically regulated via conformational change; however, our ability to manipulate these structural changes and control function is limited. Here we install a conformational switch for allosteric activation into the kinesin-1 microtubule motor in vitro and in cells. Kinesin-1 is a heterotetramer that accesses open active and closed autoinhibited states. The equilibrium between these states centers on a flexible elbow within a complex coiled-coil architecture. We target the elbow to engineer a closed state that can be opened with a de novo designed peptide. The alternative states are modeled computationally and confirmed by biophysical measurements and electron microscopy. In cells, peptide-driven activation increases kinesin transport, demonstrating a primary role for conformational switching in regulating motor activity. The designs are enabled by our understanding of ubiquitous coiled-coil structures, opening possibilities for controlling other protein activities. The kinesin-1 motor protein accesses open active and closed autoinhibited states. These states are regulated by a flexible elbow within a complex coiled-coil architecture. Now, a conformational switch has been developed by engineering the elbow to create a closed state that can be controllably opened with a de novo designed peptide to increase kinesin transport inside cells.