CHARACTERIZATION OF THE PVDE GENE WHICH IS REQUIRED FOR PYOVERDINE SYNTHESIS IN PSEUDOMONAS-AERUGINOSA

Pseudomonas aeruginosa (Pa) strain PAO synthesises a siderophore, pyov erdine (Pvd), when grown under conditions of iron starvation. Pvd cons ists of a dihydroxyquinoline group attached to an 8-amino-acid-residue peptide. DNA spanning at least 78 kb of the chromosome is required fo r Pvd synthesis, but to date only three genes involved in this process have been characterised. We report the characterisation of a fourth P a gene, pvdE, which we show to be required for Pvd synthesis. The dedu ced amino acid sequence of PvdE indicates that the protein is a member of the ATP-binding-cassette (ABC) family of membrane transporter prot eins, and this is the first example of the involvement of an ABC-type protein in siderophore synthesis.