Exploiting bacterial effector proteins to uncover evolutionarily conserved antiviral host machinery
Fig 4
Structural analysis of Legionella pneumophila effector Ceg10.
A. Six structural homologs of Ceg10, shown in the same orientation with the putative active site near the top of the figure. Top row, from left: Ceg10 (this study), L. pneumophila RavJ, L. pneumophila LapG. Bottom row, from left: S. enterica SseI, S. flexneri OspI, P. savastanoi AvrPphB. Table shows these structural homologs as determined via the Dali Lite server and their PBD ID. B. The putative active site of Ceg10 with residues shown in stick representation and hydrogen bonds are shown as dotted yellow lines. The catalytic Cys (C159), Asp (D204) and His (H192) are labeled as well as residues Asp110 and Trp 206 which are hydrogen bonded to each other in both structures. In the S-nitrosylated structure, Asp110 also hydrogen bonds to the nitrosylated-C159 and van der Waals interactions occur between the aromatic ring of Trp206 and the nitrosylation moiety. C. Electron density for C159 in the native (left) and S-nitrosylated (right) Ceg10 structures. The final refined 2Fo-mDFc electron density map, contoured at the 1σ level, is shown superimposed on each residue, as well as a 180° rotation of this region. C. Superposition of native (blue) and S-nitrosylated (brown) Ceg10 structures. D. Electrostatic surface potential of both Ceg10 structures and RavJ. All structures are orientated with the putative catalytic cysteine residue in approximately the center of the surface, and the orientations between Ceg10 and RavJ correspond to protein alignments. The displayed surface is colored by electrostatic potential from -10 kT (red) to + 10 kT (blue), as calculated by the APBS plugin in PyMOL.