Cover photograph (Copyright © 2006, American Society for Microbiology. All Rights Reserved.): Conserved residue/motif analysis of HmuR by three-dimensional modeling. The three-dimensional homology model of HmuR was constructed by using the crystal structure of two homologous proteins, FepA (ferric enterobactin receptor of Escherichia coli; Protein Data Bank code, 1FEP) and BtuB (cobalamin receptor of E. coli; Protein Data Bank code, 1NQE). The model was generated by MODELLER and analyzed by DeepView/Swiss-Pdb viewer software. HmuR demonstrates a beta-barrel structure similar to that of FepA and BtuB. The conserved residues/motifs of HmuR are highlighted and presented in different colors: H95, red; H434, blue; NPDL, pink; and YRAP, yellow. (See related article in the February 2006 issue: vol. 74, page 1222.)