The ferripyoverdine receptor FpvA of Pseudomonas aeruginosa PAO1 recognizes the ferripyoverdines of P. aeruginosa PAO1 and P. fluorescens ATCC 13525

Abstract

FpvA, the ferripyoverdine outer membrane receptor of Pseudomonas aeruginosa ATCC 15692 (PAO1 strain), is not specific to the pyoverdine produced by PAO1, but is also able to recognize the structurally different (ferri)pyoverdine of P. fluorescens ATCC 13525. The specificity of FpvA was assessed by iron uptake competitions using the wild-type strains P. aeruginosa ATCC 15692 and P. fluorescens ATCC 13525 and their respective ferripyoverdines, and by fpvA gene complementation of a FpvA-deficient mutant of P. aeruginosa ATCC 15692. The receptor mutant was able to utilize none of the two pyoverdines, while the same but fpvA-complemented mutant recovered simultaneously the ability to incorporate iron thanks to each of the two siderophores. The broad specificity of recognition of FpvA is viewed as an advantage for the strain in iron competition. Moreover, it allows an interesting approach for the understanding of the recognition mechanism between a (ferri)pyoverdine and its cognate outer membrane receptor.