FIG. 4.

Assay for induction of the HIS3 gene in homologous or heterologous pairings of BMV and/or CMV 1a methyltransferase fusions. The plate on the left is supplemented with histidine, while the one on the right is not. Each doubly transformed strain was written onto plates to indicate the identity of the 1a fusion proteins. The LexA fusion is indicated above the slash, and the GAL4 fusion is indicated below the slash (i.e., LexA/GAL4).