Transcriptome analysis of Pseudomonas aeruginosa strain, with 25 mutated half-parSs (ParB binding sites)

Chromosome segregation in Pseudomonas aeruginosa is assisted by the tripartite ParAB-parS system, composed of an ATPase (ParA), a DNA-binding protein (ParB), and its target parS sequence(s). ParB forms a nucleoprotein complex around four parSs (parS1-parS4), which is positioned within the cell by ParA. Remarkably, ParB of P. aeruginosa binds to multiple heptanucleotides (half-parSs) scattered in the genome. In this work we analysed the transcriptome of P. aeruginosa with mutated 25 half-parSs forming the strongest ParB ChIP-seq peaks. Inactivation of ParB binding to even a small fraction of these sites modulated the gene expression, however this effect is most likely indirect. Overall this work suggests complex relation between ParB binding to genome and P. aeruginosa transcriptome. Overall design: Pseudomonas aeruginosa PAO1161 (leu-, r-, RifR) as well as its derivative half-parS25 were grown in LB medium at 37oC, and cells were harvested at the logarithmic phase of culture growth (OD600 of 0.5). Three independent biological replicates for each strain were used and the whole transcriptome comparison was repeated twice (Samples are labeled as Exp1 or Exp2).