Figure 2.

Stereoviews of the electron density associated with the A-motif binding site on Arp3 in the two new crystal forms. (a) Map from the P2₁2₁2₁ crystals. (b) Map from the P4₁ crystals. Details of 2F _o − F _c electron-density maps contoured at 1σ from the region of Arp3 known to bind the C-terminal EWE sequence of WASP are shown in blue. The orange models are ribbon diagrams of the backbone of Arp3 with stick figures of several key side chains based on refined data from the new crystals. The green stick figure of the C-terminal EWE sequence of WASP is positioned as in our previous work (PDB entry 3rse; Ti et al., 2011 ▸).