The minimal meningococcal ProQ protein has an intrinsic capacity for structure-based global RNA recognition

Area of Science:

• Bacteriology
• Molecular Biology
• Genetics

Background:

• FinO-domain proteins are bacterial RNA-binding proteins regulating gene expression.
• Their target specificity varies from single RNA pairs to global regulons.
• The Neisseria meningitidis ProQ protein contains only the FinO domain.

Purpose of the Study:

• To investigate the intrinsic RNA-binding selectivity of the FinO domain.
• To identify the in vivo RNA targets of Neisseria meningitidis ProQ.
• To understand the regulatory role and functional impact of this minimal ProQ protein.

Main Methods:

• UV-crosslinking, immunoprecipitation, and sequencing (UV-CLIP-seq) to identify RNA targets.
• Transcriptome analysis to assess gene expression changes upon ProQ loss.
• Phenotypic assays to evaluate ProQ's role in stress resistance and DNA repair.

Main Results:

• UV-CLIP-seq identified 16 small non-coding RNAs and 166 mRNAs bound by meningococcal ProQ.
• ProQ predominantly binds to highly structured RNA regions and stabilizes targets.
• Loss of ProQ altered transcript levels of over 250 genes, indicating global gene expression impact.
• ProQ promotes resistance to oxidative stress and aids in DNA damage repair.

Conclusions:

• The FinO domain intrinsically recognizes abundant RNA structural motifs.
• RNA-binding selectivity evolves through the acquisition of additional protein regions.
• Minimal FinO domain proteins like meningococcal ProQ can exert global regulatory control over gene expression and cellular functions.