Zinc homeostasis in Pseudomonas

In the genus Pseudomonas, zinc homeostasis is mediated by a complete set of import and export systems, whose expression is precisely controlled by three transcriptional regulators: Zur, CzcR and CadR. In this review, we describe in detail our current knowledge of these systems, their regulation, and the biological significance of zinc homeostasis, taking Pseudomonas aeruginosa as our paradigm. Moreover, significant parts of this overview are dedicated to highlight interactions and cross-regulations between zinc and copper import/export systems, and to shed light, through a review of the literature and comparative genomics, on differences in gene complement and function across the whole Pseudomonas genus. The impact and importance of zinc homeostasis in Pseudomonas and beyond will be discussed throughout this review.