The purification of the σ FpvI /FpvR 20 and σ PvdS /FpvR 20 protein complexes is facilitated at room temperature

Abstract

Bacteria contain sigma (σ) factors that control gene expression in response to various environmental stimuli. The alternative sigma factors σ FpvI and σ PvdS bind specifically to the antisigma factor FpvR. These proteins are an essential component of the pyoverdine-based system for iron uptake in Pseudomonas aeruginosa. Due to the uniqueness of this system, where the activities of both the σ FpvI and σ PvdS sigma factors are regulated by the same antisigma factor, the interactions between the antisigma protein FpvR 20 and the σ FpvI and σ PvdS proteins have been widely studied in vivo. However, difficulties in obtaining soluble, recombinant preparations of the σ FpvI and σ PvdS proteins have..