On the Ribosomal Density that Maximizes Protein Translation Rate

TL;DR

This paper uses mathematical models to determine that the optimal ribosomal density for maximizing protein translation rate is typically half of the maximum possible density, with implications for biology and synthetic applications.

Contribution

It provides a theoretical proof that the optimal ribosomal density for maximum translation rate is usually half of the maximum, using models of ribosome flow on mRNA.

Findings

Maximum translation rate occurs at half of maximal ribosomal density

Results apply to both linear and circular mRNA models

Implications for natural gene expression and synthetic biology

Abstract

During mRNA translation, several ribosomes attach to the same mRNA molecule simultaneously translating it into a protein. This pipelining increases the protein production rate. A natural and important question is what ribosomal density maximizes the protein production rate. Using mathematical models of ribosome flow along both a linear and a circular mRNA molecule we prove that typically the steady-state production rate is maximized when the ribosomal density is one half of the maximal possible density. We discuss the implications of our results to endogenous genes under natural cellular conditions and also to synthetic biology.