RluA is the major mRNA pseudouridine synthase in Escherichia coli

Area of Science:

• Molecular Biology
• RNA Biology
• Bacterial Genetics

Background:

• Pseudouridine (Ψ) is a common RNA modification found in tRNAs and rRNAs across all life domains.
• While conserved in eukaryotes, Ψ modification in bacterial mRNAs was previously unidentified.
• Understanding mRNA modifications is crucial for deciphering gene regulation.

Purpose of the Study:

• To investigate the presence and modification of pseudouridine (Ψ) in bacterial messenger RNA (mRNA).
• To identify the specific enzyme responsible for mRNA pseudouridylation in E. coli.
• To characterize the sequence and structural motifs recognized by the mRNA-modifying enzyme.

Main Methods:

• Systematic screening of all known pseudouridine synthases for mRNA modification activity in E. coli.
• High-throughput sequencing and computational analysis to identify Ψ modification sites in mRNA.
• RNA structure probing and secondary structure analysis to determine target site motifs.

Main Results:

• Pseudouridine (Ψ) modifications were discovered in E. coli mRNA for the first time.
• The enzyme RluA was identified as the primary pseudouridine synthase responsible for mRNA modification.
• RluA modifies at least 31 high-confidence sites in E. coli mRNA, targeting a specific hairpin loop motif (ΨURAA).

Conclusions:

• This study establishes pseudouridine (Ψ) modification in bacterial mRNA, with RluA as the key enzyme.
• The identified Ψ modification motif in mRNA is conserved with known targets in tRNA and rRNA.
• Pseudouridylation (Ψ) in mRNA has the potential to regulate gene expression in bacteria.