Altering translation allows E. coli to overcome chemically stabilized G-quadruplexes

Area of Science:

• Molecular Biology
• Genetics
• Microbiology

Background:

• G-quadruplex (G4) structures are formed in guanine-rich DNA/RNA and regulate key cellular processes.
• Research on G4 roles has predominantly focused on eukaryotes, with limited investigation in bacteria.
• Understanding bacterial G4s is crucial for comprehending their impact on microbial life.

Purpose of the Study:

• To investigate the cellular roles and impact of G-quadruplex structures in Escherichia coli.
• To identify bacterial genes and pathways affected by G4 stabilization.
• To elucidate the mechanisms by which G4s influence bacterial growth.

Main Methods:

• Employed a chemical-genetic approach to screen for genes affecting growth under G4-stabilizing conditions.
• Utilized chloramphenicol to modulate translation elongation rates.
• Conducted proteomic and transcriptomic analyses to assess cellular responses.

Main Results:

• Reduced levels of elongation factor Tu or slowed translation suppressed G4 stabilization effects.
• Decreased expression of translation termination/recycling proteins exacerbated G4-related growth defects.
• Proteomic/transcriptomic data revealed reduced abundance of ribosome assembly factors in G4-stabilizing conditions.

Conclusions:

• RNA G4s pose growth barriers in Escherichia coli by interfering with translation.
• Slowing the rate of translation can serve as a compensatory mechanism against G4-induced stress.
• This study provides a model for G4-RNA interactions impacting bacterial physiology.