Figure 2. ^WTCoa6 has a twin CX₉C protein fold.

(A) Cox17 (PDB 2RNB): helices are shown in green, and cysteines in the CX₉C motifs that form disulfide bonds are shown as yellow sticks. (B) Cox6B (PDB 2EIJ): helices are shown in raspberry, and cysteines in the CX₉C (or CX₁₀C) motifs that form disulfide bonds are shown as yellow sticks. (C) ^WTCoa6 (this work): helices are shown in gray, and cysteines in the CX₉C (or CX₁₀C) motifs that form disulfide bonds are shown as yellow sticks. In all panels, the positions of the corresponding motifs are shown as red arrows. In panel (B), part of the N terminus and helix α₃ in panels (B) and (C) are not colored for clarity.