FIGURE 3.

Structural consequences of Cys98 oxidation. Stereo view of the active site highlighting contacts to the cysteine sulfonic acid moiety (depicted as a stick model with green sulfur atom). Amino acids in the present structure that normally engage the two manganese ions are rendered with beige carbons. Hydrogen bond interactions with the cysteine sulfonic acid are indicated by dashed lines. The equivalent amino acids and the Mn1 and Mn2 manganese ions from PhoRtcB structure 4ISZ are superimposed and depicted as semitransparent stick models with gray carbons and semitransparent magenta spheres, respectively.