Conserved 5-methyluridine tRNA modification modulates ribosome translocation.

Area of Science:

• RNA biology
• Molecular biology
• Biochemistry

Background:

• Post-transcriptional modifications are vital for RNA function, yet many remain uncharacterized.
• The specific role of 5-methyluridine at position 54 (m⁵U54) in transfer RNAs (tRNAs) is largely unknown despite its high conservation.

Approach:

• Mass spectrometry was used to analyze tRNA modifications in cells lacking the m⁵U54 installing enzyme (TrmA/Trm2).
• In vitro assays assessed the effect of m⁵U54 deficiency on tRNA sensitivity to translocation inhibitors.
• Cell growth and gene expression were monitored in mutant strains exposed to translocation inhibitors.

Key Points:

• Loss of the m⁵U54 enzyme leads to altered tRNA modification patterns.
• m⁵U54-deficient tRNAs show reduced sensitivity to translocation inhibitors in vitro.
• Cells lacking m⁵U54 are less affected by translocation inhibitors during growth and gene expression.

Conclusions:

• m⁵U54 plays a significant role in tRNA maturation.
• m⁵U54 modulates tRNA translocation during protein synthesis.
• This modification is a key factor in maintaining cellular homeostasis under stress conditions affecting translation.