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arXiv · 1503.03928

Spatial organization of bacterial transcription and translation

Michele Castellana·Sophia Hsin-Jung Li·Ned S. Wingreen
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Abstract

In bacteria such as $\textit{Escherichia coli}$, 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 $\sim 90\%$ 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.

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Michele Castellana, Sophia Hsin-Jung Li, Ned S. Wingreen. 2015-03-13. Spatial organization of bacterial transcription and translation. https://doi.org/10.1073/pnas.1604995113

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