CHMP3 crystal packing interactions. (a) Overlay of the cores of the “tip-to-tip” dimers in the crystal lattices of CHMP38–183 (orange)16 and CHMP38–222 (blue and green). The upper subunits were aligned, and the lower subunits diverge owing to small differences in their tip-to-tip interfaces. (b) Detailed expansion of the boxed region of CHMP38–222 shown in a. Both here and in e, most side chains conformations are shown as defined in the CHMP38–183 search model, with some minor adjustments to avoid clashes. Precise description of these side chain conformations is not possible at current resolutions. (c) Subunit packing down the 31 screw axis of the CHMP31–150 crystal lattice, with a single CHMP31–150 molecule highlighted in blue. (d) Same assembly as in c, but viewed perpendicularly to the 31 screw axis. (e) Detailed expansion of the boxed area shown in d.