Domain architecture of the SET1/TRX family (a: the SET1 subfamily, b: the TRX subfamily). The divergent RNA recognition motifs (RRM) found in Arabidopsis and yeast (not identified in domain databases) are indicated by the pale color in the figure. Domains are not drawn to scale. For the TRX subfamily, representatives of two major animal subgroups differing by the positioning of the FYRN-FYRC (DAST) domains are shown. Note the presence of conserved domains between the animal and the plant representatives. For more structures see Additional file 3.