The ferric iron-binding protein of pathogenic Neisseria spp. functions as a periplasmic transport protein in iron acquisition from human transferrin.
The ferric iron-binding protein (Fbp) expressed by pathogenic Neisseria spp. has been proposed to play a central role in the high-affinity acquisition of iron from human transferrin. The results of this investigation provide evidence that Fbp participates in this process as a functional analogue of a Gram-negative periplasmic-binding protein component, which operates as a part of a general active transport process for the receptor-mediated, high-affinity transport of iron from human transferrin. Known properties of Fbp are correlated with those of other well-characterized periplasmic-binding proteins, including structural features and the reversible binding of ligand. Predictive of a periplasmic-binding protein, which functions in the high-affinity acquisition of iron, is that Fbp is a transient participant in the process of iron acquisition from human transferrin. Evidence for this is demonstrated by results of pulse-chase experiments. Taken together, the data described here and elsewhere suggest that pathogenic Neisseria spp. use a periplasmic-binding protein-mediated active transport mechanism for the acquisition of iron from human transferrin.
Chen
C Y
CY
Division of Sexually Transmitted Diseases Laboratory Research, Centers for Disease Control and Prevention, Atlanta, Georgia 30333.
Berish
S A
SA
Morse
S A
SA
Mietzner
T A
TA
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins / Q000302:isolation & purification / Q000378:metabolism*; D001692:Biological Transport; D002462:Cell Membrane / Q000378:metabolism*; D006801:Humans; D007501:Iron / Q000378:metabolism*; D007504:Iron Radioisotopes; D033862:Iron-Binding Proteins; D008954:Models, Biological; D009344:Neisseria gonorrhoeae / Q000378:metabolism* / Q000472:pathogenicity; D033902:Periplasmic Binding Proteins; D013329:Structure-Activity Relationship; D014168:Transferrin / Q000378:metabolism*
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D007504:Iron Radioisotopes; D033862:Iron-Binding Proteins; D033902:Periplasmic Binding Proteins; D014168:Transferrin; D007501:Iron