Structures of AML1 and its mutants. The structures of various AML1 mutants are presented schematically. Runt indicates the Runt domain; AD, trans-activation domain; ID, inhibitory domain; VWRPY, VWRPY motif; m, a binding region for mSin3A. R→G means a missense mutation at codon 139, which lead to a change of amino acid (R139G; single-letter amino acid code). S→A means a missense mutation at codon 249 and 266, which lead to changes of amino acids (S249A and S266A). K→R means a missense mutation at codon 24 and 43, which lead to changes of amino acid (K24R and K43R).