Fig. 2.

An evolutionary constraint-based hierarchical classification of the tyrosine kinome. The constraint-based hierarchical classification of tyrosine kinases is depicted as an Euler diagram. Each circle represents a distinct cluster of tyrosine kinases and is scaled to the number of sequences in each cluster. Clusters containing cytoplasmic tyrosine kinases are indicated with orange circles, whereas clusters containing receptor tyrosine kinases are indicated with blue circles. Clusters containing both cytoplasmic and receptor tyrosine kinases are colored gray. For more information, see supplementary file S1, Supplementary Material online.