Mapping of the Lassa virus LAMP1 binding site reveals unique determinants not shared by other old world arenaviruses
Fig 2
Structural comparison between GP1MORV and GP1LASV and the vicinity of the histidine triad.
(A) Superimposition of GP1MORV (blue) and GP1LASV (grey) (PDB: 4ZJF). The histidine triad is indicated as well as β5 & β6. Disulfides are shown with spheres for the sulfur atoms (B) The solvent accessible surfaces of GP1MORV and GP1LASV are presented on the right and left sides, respectively. The proteins are positioned as in panel ‘A’, and the histidine triads are indicated with green arrows. A red arrow marks bulky residues on GP1MORV. The surfaces are colored according to the electrostatic potential in the range of ± 5 kT/e, as calculated by APBS tools at pH 5.0. (C) A close up view of the vicinity of the histidine triad in a superimposition of GP1MORV (blue) and GP1LASV (grey). Non-conserved sites in this region are indicated. (D) Pull-down experiment of LAMP1 by the indicated GP1LASV-Fc mutants. A representative image of three independent repeats. (E). SPR analyses of GP1LASV point mutations. The various mutants in GP1LASV were injected as analytes at 450 nM over immobilized distal domain of LAMP1. WT GP1LASV was injected multiple times at the beginning, middle and end of the injection series to monitor the consistency of the immobilized LAMP1, producing indistinguishable sensograms (only a representative curve is shown). The binding curves were manually inspected and binned into three groups: showing no or very little effect on binding (light-blue background), moderately reduced binding (pink background), and strongly diminished binding (purple background).