Figure 3.

The insertion of two amino acids into Gal3p converts it into a galactokinase. Plasmids expressing Gal1p, Gal3p, or the indicated chimera were transformed into yeast strains lacking GAL1 (Δ1), GAL3 (Δ3), or both GAL1 and GAL3 (Δ1,Δ3). Cells were then plated onto media containing either raffinose (R) or galactose (G) as the sole carbon source. Growth was monitored after 3 days incubation at 30°C. The chimeras are numbered to indicate the amino acids from Gal3p that have been replaced by the corresponding sequences from Gal1p.