FIGURE 5.

Sequence positions important for PAPSS1 and S2 discrimination. A, machine learning by random forest yields so called drop-in performance values. They are obtained by leaving out iteratively every single position of the multiple sequence alignment. Average values for all used sequence descriptors are plotted. B, 23 positions with the highest drop-in-performance values are mapped on PDB code 1XNJ. The amino acid pair Met-70/Phe-60 and Thr-85/Ser-75 being close together in space is specially highlighted (inset).