FIG. 1.

Tests for esc-E(z) interaction in the yeast two-hybrid system. (A) Growth tests with EGY48 cells containing the following combinations of plasmids are shown: left, pEG202-esc and pJG4-5-E(z), which express LexA-esc and AD-E(z), respectively; middle, pRFHMø, which does not produce a LexA protein, and pJG4-5-E(z); right, pEG202-esc and pJG4-5 (no insert). Yeast strains were streaked in parallel on media lacking leucine and containing galactose (top) or glucose (bottom). Expression of AD fusion proteins from pJG4-5 and its derivatives was induced on galactose medium but not on glucose medium. Yeast strains were grown for 4 days at 30°C. (B) X-Gal assays of yeast strains containing the following combinations of plasmids: left, pEG202-E(z) and pJG4-5-esc; middle, pEG202-E(z) and pJG4-5; right, pRFHMø and pJG4-5-esc. Yeast strains were grown for 48 h on X-Gal indicator medium containing galactose (top) or glucose (bottom).