Figure 4.—

ClustalX alignment of Su(z)2, Psc, and L(3)73Ah from Drosophila with Bmi-1 and Mel-18 from both Homo sapiens and Mus musculus. The alignment generated by ClustalX is focused on the region of the proteins located between the RF and HTH domains and begins with the last conserved cysteine residue in the RF. Amino acid positions are indicated on the left. Amino acids highlighted in red are identical (equivalent to “*” in ClustalX) among the proteins indicated, while strongly conserved amino acids (equivalent to “:” in ClustalX) are highlighted in yellow. More weakly conserved amino acids (equivalent to “.” in ClustalX) are not highlighted. The CSR1 core sequence is underlined twice, with the Su(z)2^s20 mutation indicated above. The Su(z)2¹ missense mutation is shown to the right of CSR1. Residues that correspond to α-helical regions 3 and 4 in the Bmi-1/Ring1B structure are shown. The CSR2 core sequence is underlined once, with the Su(z)2^s21 mutation indicated above.