Details of the interaction between UbcH5a and the CHIP U-box. The view in panel C is zoomed out from that in panels A and B. For clarity, only side-chain or main-chain atoms of some residues are shown. Panels on the right show molecular surface representations of the CHIP U-box. A. Closeup of the hydrophobic packing between UbcH5a (yellow) and CHIP (blue). The interacting secondary structure elements and residues are labelled in black (UbcH5a) or blue (CHIP). B. "Back" view of the complex emphasizing the hydrophobic packing between UbcH5a-loop L2 (the F62 sidechain) and the CHIP U-box. C. Polar interactions between UbcH5a and CHIP. Likely hydrogen bonds or salt bridges are shown as dotted lines. Acidic and basic side chains that are in proximity but not close enough or in the correct geometry to form salt bridges are marked with question marks.