Molecular Motor or Molecular Clock: A Question of Load

TL;DR

This paper explores how molecular motors can produce either work or timing information depending on load, based on the ratio of stepping rates and free energy changes.

Contribution

It introduces a framework linking load-dependent stepping rates to the dual output of work and information in molecular motors.

Findings

At stall force, motors produce work only.

At zero force, motors produce timing information only.

The ratio of backward to forward steps varies exponentially with load.

Abstract

The output of a motor is work, while the output of a clock is information. Here it is discussed how a molecular motor can produce both, work and information, depending on the load. If the ratio of the backward and forward stepping rates of a molecular motor increases exponentially with load, the change in free energy per step can be used to produce only work (at stall force) or only timing information (at zero force), or anything in between.