Pseudomonas aeruginosa Biofilm Matrix Polysaccharide Psl is Regulated Transcriptionally by RpoS and Post-Transcriptionally by RsmA
Extracellular polysaccharides are important components of biofilms. In non-mucoid Pseudomonas aeruginosa strains, the Pel and Psl polysaccharides are major structural components of the biofilm matrix. In this study, we demonstrate that the alternative σ-factor RpoS is a positive transcriptional regulator of psl gene expression. Furthermore, we show that psl mRNA has an extensive 5′ untranslated region, to which the post-transcriptional regulator RsmA binds and represses psltranslation. Our observations suggest that upon binding RsmA, the region spanning the ribosome binding site of psl mRNA folds into a secondary stem-loop structure that blocks the Shine–Dalgarno sequence, preventing ribosome access and protein translation. This constitutes a novel mechanism for translational repression by this family of regulators.
Copyright © 2010, John Wiley & Sons
John Wiley & Sons
Irie, Yasuhiko; Starkey, Melissa; Edwards, Adrianne N.; Wozniak, Daniel J.; Romeo, Tony; and Parsek, Matthew R., "Pseudomonas aeruginosa Biofilm Matrix Polysaccharide Psl is Regulated Transcriptionally by RpoS and Post-Transcriptionally by RsmA" (2010). Biology Faculty Publications. 205.