Modelling Polar Retention of Complexes in Escherichia coli

Abstract

The cytoplasm of Escherichia coli is a crowded, heterogeneous environment. The spatial kinetics and heterogeneities of synthetic RNA-protein complexes have been recently studied using single-cell live imaging. A strong polar retention of these complexes due to the presence of the nucleoid has been suggested based on their history of positions and long-term spatial distribution. Here, using stochastic modelling, we examine likely sources, which can reproduce the reported long-term spatial distribution of the complexes. Based on the anisotropic displacement distribution observed at the border between the mid-cell and poles, we conclude that the original hypothesis that the observed long-term behavior is the result of macromolecular crowding holds.