The FinO/ProQ-like protein PA2582 impacts antimicrobial resistance in .

Bacteria employ small regulatory RNAs (sRNA) and/or RNA binding proteins (RBPs) to respond to environmental cues. In , the FinO-domain containing RBP ProQ associates with numerous sRNAs and mRNAs, impacts sRNA-mediated riboregulation or mRNA stability by binding to 5'- or 3'-untranslated regions as well as to internal stem loop structures. Global RNA-protein interaction studies and sequence comparisons identified a ProQ-like homolog (PA2582/ProQ ) in (). To address the function of ProQ , at first a comparative transcriptome analysis of the strains PAO1 and PAO1Δ was performed. This study revealed more than 100 differentially abundant transcripts, affecting a variety of cellular functions. Among these transcripts were and , encoding the PprA/PprB two component system, , encoding a transcriptional activator of , and , encoding the outer membrane protein OprI. RNA co-purification experiments with Strep-tagged ProQ protein corroborated an association of ProQ with these transcripts. In accordance with the up-regulation of the , , and genes in strain PAO1Δ a phenotypic analysis revealed an increased susceptibility toward the aminoglycosides tobramycin and gentamicin in biofilms. Conversely, the observed down-regulation of the gene in PAO1Δ could be reconciled with a decreased susceptibility toward the synthetic cationic antimicrobial peptide GW-Q6. Taken together, these studies revealed that ProQ is an RBP that impacts antimicrobial resistance in .