Survey on newly characterized iron uptake systems of Yersinia enterocolitica.

Iron assimilation systems have been shown to be important for virulence in Yersinia enterocolitica. In principle, iron transport in Y. enterocolitica is similarly organized as in Escherichia coli although some differences exist in the siderophores used. A TonB function was identified which in a tonB mutant was complemented by the E. coli tonB gene. Three outer membrane receptors for siderophores were cloned and sequenced: FoxA for ferrioxamine B and E, FcuA for ferrichrome and HemR for heme uptake. In addition, two receptors were identified by mutants: CccA for catechol cephalosporins and FyuA for yersiniabactin, the siderophore produced by virulent yersiniae. In addition, the FyuA protein is assumed to be the pesticin receptor.