title: Quinolobactin, a new siderophore of Pseudomonas fluorescens ATCC 17400, the production of which is repressed by the cognate pyoverdine.
abstract: Transposon mutant strain 3G6 of Pseudomonas fluorescens ATCC 17400 which was deficient in pyoverdine production, was found to produce another iron-chelating molecule; this molecule was identified as 8-hydroxy-4-methoxy-quinaldic acid (designated quinolobactin). The pyoverdine-deficient mutant produced a supplementary 75-kDa iron-repressed outer membrane protein (IROMP) in addition to the 85-kDa IROMP present in the wild type. The mutant was also characterized by substantially increased uptake of (59)Fe-quinolobactin. The 75-kDa IROMP was produced by the wild type after induction by quinolobactin-containing culture supernatants obtained from the pyoverdine-negative mutant or by purified quinolobactin. Conversely, adding purified wild-type pyoverdine to the growth medium resulted in suppression of the 75-kDa IROMP in the pyoverdine-deficient mutant; however, suppression was not observed when Pseudomonas aeruginosa PAO1 pyoverdine, a siderophore utilized by strain 3G6, was added to the culture. Therefore, we assume that the quinolobactin receptor is the 75-kDa IROMP and that the quinolobactin-mediated iron uptake system is repressed by the cognate pyoverdine.
authors.affiliation: Department of Immunology, Parasitology, and Ultrastructure, Flanders Interuniversity Institute for Biotechnology, Belgium.
authors.forename: D
authors.initials: D
authors.lastname: Mossialos
authors.forename: J M
authors.initials: JM
authors.lastname: Meyer
authors.forename: H
authors.initials: H
authors.lastname: Budzikiewicz
authors.forename: U
authors.initials: U
authors.lastname: Wolff
authors.forename: N
authors.initials: N
authors.lastname: Koedam
authors.forename: C
authors.initials: C
authors.lastname: Baysse
authors.forename: V
authors.initials: V
authors.lastname: Anjaiah
authors.forename: P
authors.initials: P
authors.lastname: Cornelis
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism; D003470:Culture Media / Q000737:chemistry; D004251:DNA Transposable Elements; D004591:Electrophoresis, Polyacrylamide Gel; D007501:Iron / Q000378:metabolism; D016254:Mutagenesis, Insertional; D009842:Oligopeptides; D010860:Pigments, Biological / Q000378:metabolism / Q000494:pharmacology*; D011551:Pseudomonas fluorescens / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D011804:Quinolines; D017262:Siderophores / Q000096:biosynthesis*
chemical_list: D001425:Bacterial Outer Membrane Proteins; D003470:Culture Media; D004251:DNA Transposable Elements; D009842:Oligopeptides; D010860:Pigments, Biological; D011804:Quinolines; D017262:Siderophores; C404845:quinolobactin; C042453:pyoverdin; D007501:Iron