Crystal Structure of Outer Membrane Protein NMB0315 from Neisseria meningitidis
Figure 2
The catalytic pocket of NMB0315.
(A) The metal ion binding site. Nitrogen, oxygen and carbon atoms are colored blue, red and cyan, respectively. The metal ion and water molecules are shown as red and yellow balls, respectively. The initial experimental electron density map calculated from the SAD phases is shown contoured at 14σ in black. Hydrogen bonds are shown as red dashed lines. (B) The superposition of the active site of NMB0315 onto LasA. The side chains of conserved residues are shown as sticks, and the main chain is shown as loops. NMB0315 is colored cyan, with the nitrogen and oxygen atoms of the side chains colored blue and red, respectively. LasA is colored gray. The metal ions of NMB0315 and LasA in the active sites are represented as red and light pink spheres, respectively. (C) Sequence alignment of NMB0315, Vly and LytM. Secondary structure elements of NMB0315 are shown as arrows (β-strands). The amino acids highlighted in red and denoted with asterisks are key residues in the active site that are conserved across the three proteins. (D,E) The atomic absorption spectrum for the different metal elements in the purified NMB0315 protein solution. (F) ITC measurement of the binding affinity between Zn2+ and NMB0315.