Inferring Subsystem Efficiencies in Bipartite Molecular Machines

TL;DR

This paper develops bounds on the efficiencies of subsystems within bipartite molecular machines, providing insights into their performance when operating together, with applications to ATP synthase and kinesin.

Contribution

It introduces a theoretical framework for estimating subsystem efficiencies in coupled molecular machines, extending understanding beyond isolated measurements.

Findings

Derived bounds on subsystem efficiencies in bipartite molecular machines

Applied bounds to ATP synthase subunits and kinesin

Provided estimates of efficiencies in natural operating conditions

Abstract

Molecular machines composed of coupled subsystems transduce free energy between different external reservoirs, in the process internally transducing energy and information. While subsystem efficiencies of these molecular machines have been measured in isolation, less is known about how they behave in their natural setting when coupled together and acting in concert. Here we derive upper and lower bounds on the subsystem efficiencies of a bipartite molecular machine. We demonstrate their utility by estimating the efficiencies of the $\mathrm{F}_\mathrm{o}$ and $\mathrm{F}_1$ subunits of ATP synthase and that of kinesin pulling a diffusive cargo.