RESUMO
BACKGROUND: Gram negative bacteria require iron for growth and virulence. It has been shown that certain pathogenic bacteria such as Neisseria gonorrhoeae possess a periplasmic protein called ferric binding protein (FbpA), which is a node in the transport of iron from the cell exterior to the cytosol. SCOPE OF REVIEW: The relevant literature is reviewed which establishes the molecular mechanism of FbpA mediated iron transport across the periplasm to the inner membrane. MAJOR CONCLUSIONS: Here we establish that FbpA may be considered a bacterial transferrin on structural and functional grounds. Data are presented which suggest a continuum whereby FbpA may be considered as a naked iron carrier, as well as a Fe-chelate carrier, and finally a member of the larger family of periplasmic binding proteins. GENERAL SIGNIFICANCE: An investigation of the molecular mechanisms of action of FbpA as a member of the transferrin super family enhances our understanding of bacterial mechanisms for acquisition of the essential nutrient iron, as well as the modes of action of human transferrin, and may provide approaches to the control of pathogenic diseases. This article is part of a Special Issue entitled Transferrins: Molecular mechanisms of iron transport and disorders.
