Fig. 4.
Crystal structure of DCCPCh. (A) Overall dimeric structure of DCCPCh at dmin = 1.63 Å. One subunit is depicted by blue α-helices and violet β-strands, while the other subunit is colored from green (N terminus) via blue to red (C terminus). Iron ions in the two subclusters are shown in different colors, red (α-subcluster) and orange (β-subcluster). Sulfur atoms are colored in yellow. (B) DCC. Residues within H-bonding distance (<3.5 Å; dotted lines) to the DCC are shown. N, O, and C atoms are colored blue, purple, and black, respectively. (C) Surface and channel representation. Arrows 1 and 2 indicate two channels (cyan) per subunit. Xenon atoms are indicated as green spheres with red mesh for their anomalous scattering at 5 σ. Nearest distances between the clusters are indicated by dashed lines.