Figure 1.

Plots showing the distributions of the positions of the mutations. The sequence of the wild type is plotted, and the mutants are marked. (a) T4 lysozyme; (b) myoglobin; (c) transthyretin; (d) HIV-proteinase; (e) barnase. In T4 lysozyme, 60 of 62 mutants have the C54t and C97a mutations, in addition to the other mutations plotted here. The frequencies at these two positions are not shown. In myoglobin, 49 of 54 cases contained mutation D122n, which are also not shown. Thick bars represent the mutation positions, whereas thin bars represent the scale.