Region of β3 affected by the Leu¹¹⁷ → Trp mutation. The amino acid sequence of the region of β3 extending from residues 113 to 130 is shown in the single letter code. Leu¹¹⁷ is designated by the darker arrow and Asp¹¹⁹ by the lighter arrow. The polar and charged amino acids mutated in Bajt and Loftus23 are underlined.