Structure-function relationships in the bifunctional ferrisiderophore FpvA receptor from Pseudomonas aeruginosa.
FpvA is the primary outer membrane transporter required for iron acquisition via the siderophore pyoverdine (Pvd) in Pseudomonas aeruginosa. FpvA, like other ferrisiderophore transporters, consists of a membrane-spanning beta-barrel occluded by a plug domain. The beta-strands of the barrel are connected by large extracellular loops and periplasmic turns. Like some other TonB-dependent transporters, FpvA has a periplasmic domain involved in a signalling cascade that regulates expression of genes required for ferrisiderophore transport. Here, the structures of FpvA in different loading states are analysed in light of mutagenesis data. This analysis highlights the roles of different protein domains in Pvd-Fe uptake and the signalling cascade and reveals a strong correlation between Pvd-Fe transport and activation of the signalling cascade. It is likely that conclusions drawn for FpvA will be relevant to other TonB-dependent ferrisiderophore transport and signalling proteins.
Schalk
Isabelle J
IJ
Département Récepteurs et Protéines Membranaires, Ecole Supérieure de Biotechnologie de Strasbourg, Institut Gilbert-Laustriat UMR CNRS/Université-Strasbourg I, Illkirch, France. schalk@esbs.u-strasbg.fr
Lamont
Iain L
IL
Cobessi
David
D
D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry* / Q000378:metabolism*; D007501:Iron / Q000378:metabolism; D008958:Models, Molecular; D015394:Molecular Structure; D017433:Protein Structure, Secondary; D015398:Signal Transduction / Q000502:physiology; D013329:Structure-Activity Relationship
D001425:Bacterial Outer Membrane Proteins; C082326:FpvA protein, Pseudomonas aeruginosa; D007501:Iron