A bacterial translation activator with an intrinsically disordered RNA-binding region

Area of Science:

• Microbiology
• Molecular Biology
• Bacterial Pathogenesis

Background:

• Bacterial RNA-binding proteins (RBPs) primarily function as negative regulators of translation.
• Understanding translational control mechanisms is crucial for bacterial physiology and pathogenesis.

Purpose of the Study:

• To identify and characterize novel bacterial RBPs that act as positive regulators of translation.
• To elucidate the mechanism of action and physiological role of PhaF in *Pseudomonas aeruginosa*.

Main Methods:

• CLIP-seq and CLAP-seq were employed to identify PhaF-targeted transcripts.
• Biochemical assays were used to determine the RNA-binding mode and mechanism of translational activation.
• Genetic manipulation was used to assess the physiological role of PhaF in exopolysaccharide synthesis and biofilm formation.

Main Results:

• Identification of PhaF, a positive translational regulator in *Pseudomonas aeruginosa*, targeting over 50 transcripts.
• PhaF binds upstream of the Shine-Dalgarno sequence via KPAA motifs in an intrinsically disordered region to stimulate translation.
• PhaF's translational control of *pslA* is essential for exopolysaccharide synthesis and biofilm formation.

Conclusions:

• PhaF represents a novel class of bacterial translational activators with RNA-binding features similar to eukaryotic RBPs.
• PhaF plays a significant role in *P. aeruginosa* physiology, particularly in biofilm development.
• This discovery expands our understanding of translational regulation in bacteria.