Alignment of histone H3K9 methyltransferase consensus sequences that includes preSET, SET and postSET regions. Alignment positions are given according to D. melanogaster Su(var)3-9. Specific consensus sequences were computed from 38 Su(var)3-9, 8 dim-5, 12 G9a/GLP, 15 SETDB/EuHMTase and 19 plant SUVH proteins. 90–100%-identical residues are black boxed and 50–89%-identical ones are grey boxed for each class of orthologues. Above the proteins, amino acid substitutions found in mutant D. melanogaster Su(var)3-9 proteins [6, 34] are black shadowed. Persistently conserved consensus differences found in Su(var)3-9 proteins in comparison to other H3K9 methyltransferases are marked with an empty circle.