Fig. 2.

Details of the Josephin-2 active site. (A) The extended C-terminus of ubiquitin (yellow) threads into the active site of Josephin-2 (shown as a cyan surface representation). (B) A portion of the final 2Fo-Fc map, contoured at 1σ, showing the site of covalent attachment of the ubiquitin molecule to Cys-24. (C) Detailed view showing polar interactions between the ubiquitin C-terminus and active-site Josephin-2 residues. Hydrogen bonds shown as dashed lines are listed in the table at right. The Cys-Asp-His residues of the Josephin-2 catalytic triad are labeled. A stereo version of this panel can be found in Fig. S1. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)