subunit
Figure 2: Structure of residues 42 - 56 of the B1 subunit of staphylococcal protein G in the solid state, determined using X-ray crystallography, showing a strong cluster of hydrophobic residues required for stability of the hairpin. This aromatic interaction was also shown to be preserved in the isolated hairpin, using solution NMR studies. Two views of the hairpin are shown (PDB code: 1PGA).