FIG. 2.

Interactions between Tf1 proteins. S. cerevisiae EGY48 was cotransformed with plasmids encoding various LexA-BD fusion proteins, together with plasmids encoding B42-AD fusions. Master plates with these transformants were grown on SC-glucose leucine-plus plates and subsequently replica plated to SC-galactose leucine-minus plates. The strength of interaction was indicated by the time required for growth on medium lacking leucine. A strain with LexA-p53 and B42-SV40 T antigen was a positive control and showed clear growth after approximately 1 to 2 days (++++). +++, very strong interaction (growth after ∼2 days); ++, strong interaction (growth after ∼3 days); +, weak interaction (growth after ∼4 days); +/− and −/+, very weak interaction (growth after ∼4 to 5 days); −, no interaction (no growth after 5 days); n.d., not determined.