Bacterial noncoding Y RNAs are widespread and mimic tRNAs

Area of Science:

• Microbiology
• Molecular Biology
• RNA Biology

Background:

• Ro60 autoantigen is a ring-shaped protein found in animal cells, bound to Y RNAs (noncoding RNAs or ncRNAs).
• In Deinococcus radiodurans, Y RNA links Ro60 to polynucleotide phosphorylase, enabling structured RNA degradation.
• Ro60 orthologs are widespread in bacteria, but Y RNAs were previously identified in only two species.

Purpose of the Study:

• To investigate the prevalence of Y RNAs as Ro60 partners in bacteria.
• To characterize the structural and functional properties of newly identified bacterial Y RNAs.

Main Methods:

• Bioinformatic analysis of bacterial and phage genomes to identify Y RNA genes near Ro60 orthologs.
• Comparative genomics to identify conserved features in Y RNAs.
• Biochemical assays to assess nucleotide modifications and enzyme substrate recognition.

Main Results:

• Likely Y RNAs were identified in over 250 bacterial and phage species, often encoded near Ro60.
• A conserved domain resembling transfer RNA (tRNA) was found in at least one Y RNA per species.
• These Y RNAs possess tRNA-like nucleotide modifications and are recognized by tRNA-processing enzymes.

Conclusions:

• Y RNAs are common and important components of bacterial physiology.
• A novel class of bacterial ncRNAs that mimic tRNA has been identified.
• These findings expand the known roles of Y RNAs and tRNA-like structures in prokaryotes.