Long-Time Dynamics of Selected Molecular-Motor Components Using a Physics-Based Coarse-Grained Approach

Area of Science:

• Biophysics
• Structural Biology
• Molecular Machines

Background:

• Molecular motors are crucial for intracellular transport and movement.
• Rotatory motors are highly efficient biological machines.
• Understanding their dynamics is key to deciphering cellular processes.

Purpose of the Study:

• To investigate the long-term dynamics of specific rotatory molecular motors.
• To explore the conversion of thermal motion into net rotation.
• To elucidate the role of motor structure in biological transport.

Main Methods:

• Microcanonical and canonical molecular dynamics simulations.
• Utilized the coarse-grained UNRES force field and a lipid-membrane model.
• Simulated millisecond time scales for designed and natural rotatory motors (4YY2, 6SD5, 2BL2).

Main Results:

• Rotational motion observed with zero total angular momentum in microcanonical simulations.
• Thermal motions converted into net rotation (ratcheting) in canonical simulations for 6SD5 and 2BL2.
• Rotation direction and extent were dependent on initial conditions.

Conclusions:

• Rotatory molecular motors can harness thermal oscillations for net rotational motion.
• ATP hydrolysis likely dictates rotation direction and magnitude.
• Motor structure is fundamental for enabling biological movement and transport.