Figure 6.

ROC curves for the 1^st EC level (upper left chart); 1^st and 2^nd EC level (upper right chart); 1^st, 2^nd and 3^rd EC level (lower left chart) and for all EC levels (lower right chart). Calculation was conducted for 3,135 sequentially non-redundant structures of known function. A random ROC curve (magenta colored) is not a diagonal line (usually presented in ROC plots) because assignment of enzyme function is more complicated than a problem of bimodal classification. Clearly, the probability of assignment of an incorrect EC number is bigger (for the 1^st EC level) or much bigger (for all EC levels) than the correct one.