Title

Pseudomonas aeruginosa Biofilm Matrix Polysaccharide Psl is Regulated Transcriptionally by RpoS and Post-Transcriptionally by RsmA

Document Type

Article

Publication Date

10-2010

Publication Source

Molecular Microbiology

Abstract

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.

Inclusive pages

158–172

ISBN/ISSN

0950-382X

Comments

Permission documentation is on file.

Publisher

John Wiley & Sons

Volume

78

Issue

1

Peer Reviewed

yes