Spatial organization of bacterial transcription and translation

Abstract

In bacteria such as Escherichia coli, DNA is compacted into a nucleoid near the cell center, while ribosomes-molecular complexes that translate messenger RNAs (mRNAs) into proteins-are mainly localized at the poles. We study the impact of this spatial organization using a minimal reaction-diffusion model for the cellular transcriptional-translational machinery. Our model predicts that 90\% of mRNAs are segregated to the poles and reveals a "circulation" of ribosomes driven by the flux of mRNAs, from synthesis in the nucleoid to degradation at the poles. To address the existence of non-specific, transient interactions between ribosomes and mRNAs, we developed a novel method to efficiently incorporate such transient interactions into reaction-diffusion equations, which allowed us to quantify the biological implications of such non-specific interactions, e.g. for ribosome efficiency.

Tasks

Reproductions