Siderophore specificities of the Pseudomonas aeruginosa TonB ‐dependent transporters ChtA and ActA

Iron is a key nutrient for the growth of almost all bacteria. The pathogenPseudomonas aeruginosa is able to express at least 15 different iron acquisition pathways, each involving a specific outer membrane transporter. Most of these iron-uptake pathways rely on small iron chelators (siderophores) produced by other microorganisms. We identified the outer membrane transporters involved in the uptake of ironvia two α-carboxylate siderophores and three mixed α-carboxylate/hydroxamate siderophores. Iron is an essential nutrient for the survival and virulence ofPseudomonas  aeruginosa. The pathogen expresses at least 15 different iron-uptake pathways, the majority involving small iron chelators called siderophores.P.  aeruginosa produces two siderophores, but can also use many produced by other microorganisms. This implies that the bacterium expresses appropriate TonB-dependent transporters (TBDTs) at the outer membrane to import the  ferric form of each of the siderophores used. Here, we show that the two α-carboxylate-type siderophores rhizoferrin-Fe and staphyloferrin A-Fe are transported intoP.  aeruginosa cells by the TBDT ActA. Among the mixed α-carboxylate/hydroxamate-type siderophores, we found aerobactin-Fe to be transported by ChtA and schizokinen-Fe and arthrobactin-Fe by ChtA and another unidentified TBDT. Our findings enhance the understanding of the adaptability ofP.  aeruginosa and hold significant implications for developing novel strategies to comba...
Source: FEBS Letters - Category: Biochemistry Authors: Tags: Research Letter Source Type: research