Altering translation allows E. coli to overcome G-quadruplex stabilizers

G-quadruplex (G4) structures can form in guanine-rich DNA or RNA and have
been found to modulate cellular processes including replication,
transcription, and translation. Many studies on the cellular roles of G4s
have focused on eukaryotic systems, with far fewer probing bacterial G4s.
Using a chemical-genetic approach, we identified genes in Escherichia coli
that are important for growth in G4-stabilizing conditions. Reducing
levels of elongation factor Tu or slowing translation elongation with
chloramphenicol suppress the effects of G4 stabilization. In contrast,
reducing the expression of certain translation termination or ribosome
recycling proteins is detrimental to growth in G4-stabilizing conditions.
Proteomic and transcriptomic analyses demonstrate that ribosome assembly
factors and other proteins involved in translation are less abundant in
G4-stabilizing conditions. Our results suggest that RNA G4s can present
barriers to E. coli growth and reducing the rate of translation
can compensate for G4-related stress.