Mutational alterations in the DNA binding and heterodimerization activities of the Runt domain. (A) The partial AML1 proteins indicated above the panel were produced in E coli and subjected to EMSA. Symbols + and − signify the presence and absence of the β2 subunit, respectively. (B) The indicated partial AML1 proteins were subjected to an affinity column assay. M, molecular weight marker; β, PEBP2β2; A, input AML1 protein; W, unbound proteins in washed fractions; E, bound proteins eluted at 250 mmol/L imidazole. The bands marked with open triangles indicate the β subunits associated with AML1 proteins.