Distribution of the different MAPK activation loop motifs in different groups of fungal MAPKs.

The activation loop T-E-Y and T-G-Y motifs are distributed in all four groups. The activation loop motif T-S-Y is unique to group A. The activation loop motif T-H-Y is distributed in groups A and B. The activation loop motifs S-D-Y, S-E-Y, T-T-Y and T-I-Y are unique to group D, while the K-G-Y motif is unique to groups A and C.