High-Resolution Structure of an Alternate Form of the Ferric Ion Binding Protein from Haemophilus influenzae

Even though a closed form of the holo H9Q FbpA mutant was not realized in this study, the X-ray crystallography portrays an interesting open form of FbpA that can bind Fe3+ along with a large chelator molecule (EDTA). The observation that Fe3+ can bind to the C-terminal tyrosines 195 and 196 without coordination from the N-terminal half of the protein, and that synergistic ions other than phosphate will bind in the anion binding site suggests that some other chelates of Fe3+ might bind to the protein as well. This alternate structural state of FbpA therefore offers further insight into the iron uptake and release mechanism of FbpA and provides a basis for further research.

Duke Scholars

Author Alvin L. Crumbliss Chemistry