Fig. 3. The 3–7 Å size systems for HDAC8 from nuclear configuration 2. The 3 Å system consists of the central Zn²⁺ ion (white sphere), substrate (subs), water molecule (Ow), D178, H180, and D267, all shown in ball and stick model. The 4 Å system adds L179 and Y306, shown with stick model highlighted in red. 5 Å adds H142, H143, and G304, stick model highlighted in blue. 6 Å includes G303, highlighted in green. The largest 7 Å system includes a K⁺ ion (purple sphere) and C153, H181, P209, G265, A266, T268, M274, and G305, shown with non-highlighted stick model.