Related Experiment Video
Updated: Aug 2, 2026

Light-driven Molecular Motors on Surfaces for Single Molecular Imaging
Published on: March 13, 2019
Structure of a genetically engineered molecular motor
W Kliche1, S Fujita-Becker, M Kollmar
1Department of Biophysics, Max Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany. kull@mpimf-heidelberg.mpg.de
Abstract:
Molecular motors move unidirectionally along polymer tracks, producing movement and force in an ATP-dependent fashion. They achieve this by amplifying small conformational changes in the nucleotide-binding region into force-generating movements of larger protein domains. We present the 2.8 A resolution crystal structure of an artificial actin-based motor. By combining the catalytic domain of myosin II with a 130 A conformational amplifier consisting of repeats 1 and 2 of alpha-actinin, we demonstrate that it is possible to genetically engineer single-polypeptide molecular motors with precisely defined lever arm lengths and specific motile properties. Furthermore, our structure shows the consequences of mutating a conserved salt bridge in the nucleotide-binding region. Disruption of this salt bridge, which is known to severely inhibit ATP hydrolysis activity, appears to interfere with formation of myosin's catalytically active 'closed' conformation. Finally, we describe the structure of alpha-actinin repeats 1 and 2 as being composed of two rigid, triple-helical bundles linked by an uninterrupted alpha-helix. This fold is very similar to the previously described structures of alpha-actinin repeats 2 and 3, and alpha-spectrin repeats 16 and 17.
Related Concept Videos
Mechanical Protein Functions
Overview of Myosin Structure and Function
Microtubule Associated Motor Proteins
The Movement of Organelles and Vesicles
Microtubules in Cell Motility
Mechanical Protein Function

