# Cold Shock Proteins Mediate Transcription of Ribosomal RNA in Escherichia coli Under Cold-Stress Conditions

## TL;DR

This study shows that multiple cold-shock proteins in E. coli work together to support ribosome production and growth in cold environments.

## Contribution

The study reveals that CspA, CspE, and CspI collectively mediate 16S rRNA synthesis under cold stress.

## Key findings

- Single deletions of CspA, CspE, or CspI had minimal impact on growth and rRNA synthesis at low temperatures.
- Double and triple deletions of these genes significantly impaired 16S rRNA synthesis and cold adaptation.
- The findings suggest redundant mechanisms compensate for the loss of individual cold-shock proteins.

## Abstract

Escherichia coli displays strong adaptability for growth and reproduction at low temperatures, with ribosome biogenesis being a critical process for its growth in cold environments. The cold-shock proteins (CSPs) encompass a protein family that can assist bacterial growth at low temperatures by acting as molecular chaperones. In this study, we investigated whether CSP CspA, CspE, and CspI affect ribosomal RNA (rRNA) transcription. Deletion of the single genes encoding these proteins had only a very marginal effect on cellular growth at low temperatures, and rRNA synthesis was hardly affected. Double and triple deletion of the genes encoding these proteins resulted in a much stronger phenotype providing evidence that CspA, CspE, and CspI play an essential role in maintaining 16S rRNA synthesis and enabling optimal cellular growth at low temperatures. These findings suggest the existence of efficient backup mechanisms able to compensate for the absence of a single CSP.