Error-speed correlations in biopolymer synthesis

TL;DR

This study investigates the stochastic fluctuations in error rates and synthesis speed of biopolymers, revealing that these quantities are correlated and depend on the enzyme's error-correction mechanisms, which can be identified through experimental measurements.

Contribution

It demonstrates the correlation between error and speed fluctuations in biopolymer synthesis and links these correlations to specific enzyme error-correction mechanisms.

Findings

Faster synthesis correlates with either better or worse errors, depending on the mechanism.

Discrimination in forward reaction rates improves accuracy for faster synthesis.

Discrimination in monomer rejection rates leads to different error-speed relationships.

Abstract

Synthesis of biopolymers such as DNA, RNA, and proteins are biophysical processes aided by enzymes. Performance of these enzymes is usually characterized in terms of their average error rate and speed. However, because of thermal fluctuations in these single-molecule processes, both error and speed are inherently stochastic quantities. In this paper, we study fluctuations of error and speed in biopolymer synthesis and show that they are in general correlated. This means that, under equal conditions, polymers that are synthesized faster due to a fluctuation tend to have either better or worse errors than the average. The error-correction mechanism implemented by the enzyme determines which of the two cases holds. For example, discrimination in the forward reaction rates tends to grant smaller errors to polymers with faster synthesis. The opposite occurs for discrimination in monomer rejection rates. Our results provide an experimentally feasible way to identify error-correction mechanisms by measuring the error-speed correlations.