FpvB, an alternative type I ferripyoverdine receptor of Pseudomonas aeruginosa.
Under conditions of iron limitation, Pseudomonas aeruginosa secretes a high-affinity siderophore pyoverdine to scavenge Fe(III) in the extracellular environment and shuttle it into the cell. Uptake of the pyoverdine-Fe(III) complex is mediated by a specific outer-membrane receptor protein, FpvA (ferripyoverdine receptor). Three P. aeruginosa siderovars can be distinguished, each producing a different pyoverdine (type I-III) and a cognate FpvA receptor. Growth of an fpvA mutant of P. aeruginosa PAO1 (type I) under iron-limiting conditions can still be stimulated by its cognate pyoverdine, suggesting the presence of an alternative uptake route for type I ferripyoverdine. In silico analysis of the PAO1 genome revealed that the product of gene PA4168 has a high similarity with FpvA. Inactivation of PA4168 (termed fpvB) in an fpvA mutant totally abolished the capacity to utilize type I pyoverdine. The expression of fpvB is induced by iron limitation in Casamino acids (CAA) and in M9-glucose medium, but, unlike fpvA, not in a complex deferrated medium containing glycerol as carbon source. The fpvB gene was also detected in other P. aeruginosa isolates, including strains producing type II and type III pyoverdines. Inactivation of the fpvB homologues in these strains impaired their capacity to utilize type I ferripyoverdine as a source of iron. Accordingly, introduction of fpvB in trans restored the capacity to utilize type I ferripyoverdine.
Ghysels
Bart
B
Flanders Interuniversity Institute of Biotechnology (VIB6), Laboratory of Microbial Interactions, Vrije Universiteit Brussel, Building E, room 6·6, Pleinlaan 2, B-1050 Brussels, Belgium.
Dieu
Bui Thi Min
BTM
Flanders Interuniversity Institute of Biotechnology (VIB6), Laboratory of Microbial Interactions, Vrije Universiteit Brussel, Building E, room 6·6, Pleinlaan 2, B-1050 Brussels, Belgium.
Beatson
Scott A
SA
Institute for Biomedical Research, Medical School, University of Birmingham, Birmingham B15 2TT, United Kingdom.
Pirnay
Jean-Paul
JP
Epidemiology and Bio-statistics Division, Department of Well-being, Queen Astrid Military Hospital, B-1120 Brussels, Belgium.|Flanders Interuniversity Institute of Biotechnology (VIB6), Laboratory of Microbial Interactions, Vrije Universiteit Brussel, Building E, room 6·6, Pleinlaan 2, B-1050 Brussels, Belgium.
Ochsner
Urs A
UA
Department of Microbiology, University of Colorado Health Sciences Center, Denver, CO 80262, USA.
Vasil
Michael L
ML
Department of Microbiology, University of Colorado Health Sciences Center, Denver, CO 80262, USA.
Cornelis
Pierre
P
Flanders Interuniversity Institute of Biotechnology (VIB6), Laboratory of Microbial Interactions, Vrije Universiteit Brussel, Building E, room 6·6, Pleinlaan 2, B-1050 Brussels, Belgium.
D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D015964:Gene Expression Regulation, Bacterial; D007501:Iron / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D009842:Oligopeptides; D010860:Pigments, Biological / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D017262:Siderophores / Q000378:metabolism*
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; C082326:FpvA protein, Pseudomonas aeruginosa; D009842:Oligopeptides; D010860:Pigments, Biological; D017262:Siderophores; C042453:pyoverdin; D007501:Iron