Stereo Images of Ubc9-RanGAP1 Interaction. (A and B) Orthogonal orientations of the Ran-GAP1 consensus motif in complex with Ubc9. Amino acids are indicated by type, number, or both. Ubc9 Glu98 and Asp100 are removed in (B). (C) RanGAP1-Ubc9 interaction outside the motif recognition interface. Helices lettered for RanGAP1 (F and H) and Ubc9 (C). Backbonepositions are represented by ribbon spline (RanGAP1 in yellow, Ubc9 in blue), theoretical hydrogen bonds are dotted lines, and waters are red spheres. * Reprinted from Cell, 108 (3), Bernier-Villamor V, Sampson DA, Matunis MJ and Lima, CD, Structural basis for E2-mediated SUMO conjugation revealed by a complex between ubiquitin-conjugating enzyme Ubc9 and RanGAP1, 345-356., Copyright (2002), with permission from Elsevier.