A, a detailed representation of the three regions of interaction. On the bottom right, the interactions between β1 of one monomer and β6 of the other are shown. Likewise, interactions are shown on the bottom left, between a section of β2 and β3 and top left, between β2 of one monomer and its symmetrical segment from the second monomer. Only half of the total interactions per dimer are shown; a corresponding half is formed in the other part of the dimer. B, hydrophobic side chains from strands β1 and β2 of one molecule blue) are buried by residues from the complementary molecule (red). For clarity only the relevant parts of each molecule are displayed. Two views related by a 90° rotation are shown.