The molecular surface model of the monomer from nsp4C (T408-Q496) WT dimer and mutant C425S.

<p>Electrostatic potential is mapped on the surface, with positive charged region colored in blue and negative charged region in red. Both molecules in one asymmetric unit of the WT nsp4C dimer and mutant C425S are shown in three orientations. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0006217#pone-0006217-g003" target="_blank">Fig. 3A and 3B</a> represents molecule A and molecule B of the WT nsp4C dimer respectively; while <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0006217#pone-0006217-g003" target="_blank">Fig. 3C</a> represents the monomer of the C425S mutant. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0006217#pone-0006217-g003" target="_blank">Fig. 3D</a> represents the superposition of molecule A (gold) and B (magenta) from WT and the monomer of the C425S mutant (green), Cys425 is shown in stick representation, with the carbon, nitrogen, oxygen, and sulfur atoms colored yellow, blue, red, and green, respectively; and also the crystal packing of WT nsp4C (magenta), symmetry-related molecules are colored in green, and the molecule forming the equivalent of the C425S mutant dimer is colored in blue. Selected amino acids are labeled, and the figure is drawn by PyMol <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0006217#pone.0006217-DeLano1" target="_blank">[47]</a>.