Efficiencies of a molecular motor: A generic hybrid model applied to the F1-ATPase

TL;DR

This paper presents a hybrid model for molecular motor efficiency, explicitly considering elastic coupling, and applies it to F1-ATPase, achieving good agreement with experimental data and clarifying efficiency conditions.

Contribution

A simple, explicit elastic coupling model for molecular motors is developed and applied to F1-ATPase, providing new insights into efficiency behaviors.

Findings

Good quantitative agreement with experimental data

Identified conditions where efficiency exceeds one

Clarified the role of elastic coupling in motor efficiency

Abstract

In a single molecule assay, the motion of a molecular motor is often inferred from measuring the stochastic trajectory of a large probe particle attached to it. We discuss a simple model for this generic set-up taking into account explicitly the elastic coupling between probe and motor. The combined dynamics consists of discrete steps of the motor and continuous Brownian motion of the probe. Motivated by recent experiments on the F1-ATPase, we investigate three types of efficiencies both in simulations and a Gaussian approximation. Overall, we obtain good quantitative agreement with the experimental data. In particular, we clarify the conditions under which one of these efficiencies becomes larger than one.