Crystal structures have been solved for two bacterial outer membrane proteins, FhuA and FepA, which mediate active transport of chelated iron. Analysis of ligand-induced changes in the structure of FhuA has provided our first structural insights into an active transport mechanism for a complex solute.
Laboratory of Molecular Biophysics, Department of Biochemistry, The University of Oxford, The Rex Richards Building, South Parks Road, Oxford, OX1 3QU, UK. mark@biop.ox.ac.uk