Microbiology
PvdM of fluorescent pseudomonads is required for the oxidation of ferribactin by PvdP in periplasmic pyoverdine maturation
Fluorescent pseudomonads such as Pseudomonas aeruginosa or Pseudomonas fluorescens produce pyoverdine siderophores that ensure iron-supply in iron-limited environments. After its synthesis in the cytoplasm, the nonfluorescent pyoverdine precursor ferribactin is exported into the periplasm, where the enzymes PvdQ, PvdP, PvdO, PvdN, and PtaA are responsible for fluorophore maturation and tailoring steps. While the roles of all these enzymes are clear, little is known about the role of PvdM, a human renal dipeptidase–related protein that is predicted to be periplasmic and that is essential for pyoverdine biogenesis.PvdO is required for the oxidation of dihydropyoverdine as the last step of fluorophore formation in Pseudomonas fluorescens
Pyoverdines are important siderophores that guarantee iron supply to important pathogenic and non-pathogenic pseudomonads in host habitats. A key characteristic of all pyoverdines is the fluorescent dihydroxyquinoline group that contributes two ligands to the iron complexes. Pyoverdines are derived from the non-ribosomally synthesized peptide ferribactin, and their fluorophore is generated by periplasmic oxidation and cyclization reactions of d-tyrosine and l-diaminobutyric acid. The formation of the fluorophore is known to be driven by the periplasmic tyrosinase PvdP.
