Ferrioxamine uptake in Yersinia enterocolitica: characterization of the receptor protein FoxA

Abstract
The gene for the high‐affinity outer membrane ferrioxamine receptor FoxA of Yersinia enterocolitica was cloned in Escherichia coli K‐12. A foxA mutant of Yersinia could be complemented by the cloned DNA fragment. The FoxA encoding region was sequenced and an open reading frame encoding 710 amino acids, including a signal sequence of 26 amino acids, was deduced. The mature FoxA protein consisted of 684 amino acids and had a molecular mass of 75768 Da. FoxA shared 33% amino acid sequence homology with FhuA, the ferrichrome receptor of Escherichia coli. Based on the homologies with FhuA and other TonB‐dependent receptors a topological model of FoxA is presented.