Anchor Peptide of Transferrin-binding Protein B Is Required for Interaction with Transferrin-binding Protein A

作者：Yang Xue; Yu Rong hua; Calmettes Charles; Moraes Trevor F; Schryvers Anthony B^*

来源：Journal of Biological Chemistry, 2011, 286(52): 45165-45173.

DOI：10.1074/jbc.M110.214171

Gram-negative bacterial pathogens belonging to the Pasteurellaceae, Moraxellaceae, and Neisseriaceae families rely on an iron acquisition system that acquires iron directly from host transferrin (Tf). The process is mediated by a surface receptor composed of transferrin-binding proteins A and B (TbpA and TbpB). TbpA is an integral outer membrane protein that functions as a gated channel for the passage of iron into the periplasm. TbpB is a surface-exposed lipoprotein that facilitates the iron uptake process. In this study, we demonstrate that the region encompassing amino acids 7-40 of Actinobacillus pleuropneumoniae TbpB is required for forming a complex with TbpA and that the formation of the complex requires the presence of porcine Tf. These results are consistent with a model in which TbpB is responsible for the initial capture of iron-loaded Tf and subsequently interacts with TbpA through the anchor peptide. We propose that TonB binding to TbpA initiates the formation of the TbpB-TbpA complex and transfer of Tf to TbpA.

• 出版日期2011-12-30