ZnuA and zinc homeostasis in Pseudomonas aeruginosa

Abstract

Pseudomonas aeruginosa is a ubiquitous environmental bacterium and a clinically significant opportunistic human pathogen. Central to the ability of P. aeruginosa to colonise both environmental and host niches is the acquisition of zinc. Here we show that P. aeruginosa PAO1 acquires zinc via an ATP-binding cassette (ABC) permease in which ZnuA is the high affinity, zinc-specific binding protein. Zinc uptake in Gram-negative organisms predominantly occurs via an ABC permease, and consistent with this expectation a P. aeruginosa Î "znuA mutant strain showed an ∼60% reduction in cellular zinc accumulation, while other metal ions were essentially unaffected. Despite the major reduction in zinc ac..