Fig. 1. Classification of murine SET domain proteins. An exhaustive search for SET domains in the mouse genome revealed 50 proteins that were grouped into 11 subclasses using a tree based on a structure-based multiple sequence alignment (see Materials and methods). The tree is shown on the left with protein Accession Number and names. The most likely target specificity for each group is indicated. The most prominent SET domain co-domains are listed in the right-most column. Accession Numbers are for UniProt except those indicated in blue italic, which are from Ensembl (release 30.33f; the full Accession Number is of the form ENSMUSP000000xxxxx, and only the last five digits are shown), and for HYPB, which is a NCBI RefSeq entry. For the PRDM group, the protein names for the human orthologs are given. For the SMYD group, only 3 out of 5 members were included in the alignment, and for the PRDM group, only 7 of 15 members were included. Mll2, which resides on mouse chromosome 7, has also been called MLL4 and Wbp7 (FitzGerald and Diaz, 1999; Huntsman et al., 1999; Bedford et al., 1997).