FIGURE 8.

Previously unobserved residues modeled in the Methylocystis sp. str. Rockwell pMMO pmoC subunit. Residues 200–210 (magenta) are ordered in the zinc-soaked structure and provide a fourth amino acid ligand, Glu-201, to the zinc site. The simulated annealing composite omit map is superimposed in gray (1σ). The C-terminal residue of this stretch, Glu-210, may connect to either the C terminus of pmoC within the same protomer (chain G, intervening disordered residues denoted with a dotted line) or to the C terminus of pmoC within the neighboring protomer (chain K).