Figure 6.

Ribbon depiction of the folding of subunit c derived from the NMR structure. The “front” and “back” face of two subunits c are indicated. A functional c₂ dimer is proposed to be formed by packing the front face of one monomer against the back face of a second monomer (46), i.e., with D61 of one monomer packed between A24 and A62 of a second monomer. The positions of the backbone atoms of key residues discussed in the text are indicated. The illustration was done in the program molmol (45).