Protein domains enriched in kinase- and substrate subtypes. Example of protein domains annotated on the amino acid sequences of kinases and their substrates using PROSITE web tool screen shot (A), their statistical enrichment among kinase and substrate subtypes (B). The horizontal axis in B identifies the kinase (substrate) subtype (agc, atp, camk, ck1, cmgc, other, rgc, ste, TK, tkl) in the notation . The vertical axes on the left refer to the identity index of statistically enriched domains in these subgroups of proteins (see Additional File 1 for key to the index). The scale on the right shows the - log p value of statistical enrichment of domains in these protein subgroups.