Researchers from the Max Planck Institute and other institutions have discovered a novel GTP-powered molecular motor consisting of two proteins, Rab5 and EEA1. Unlike traditional molecular motors that rely on ATP for energy, this two-component motor utilizes GTP, providing a new perspective on cellular mechanics and synthetic protein design. The study shows that Rab5 triggers a flexibility change in the EEA1 protein, which mimics a Stirling engine’s operation by alternating between rigid and flexible states, facilitating cargo distribution to membrane-bound organelles.
This groundbreaking work highlights that GTPases, previously thought to be predominantly signaling molecules, can also generate mechanical work. The team, led by researchers including Joan Antoni Soler and Anupam Singh, used modified EEA1 proteins to observe dynamics via advanced microscopes, confirming the motor system. This system exhibits comparable thermodynamic efficiency to conventional ATP-driven motors, suggesting a conserved mechanism across various cellular compartments.
The findings potentially open avenues in biophysics and molecular cell biology, presenting opportunities for developing synthetic protein engines inspired by this new class of molecular motors, which function through localized mechanical work rather than movement along structures like microtubules. The results were published in Nature Physics.
