Figure 1.

Phenotypes associated with yeast cells lacking UBL/UBA-containing genes. Mutants display stress-sensitive phenotypes. Isogenic yeast strains were grown to an optical density A₆₀₀ of ∼1.2, and fourfold dilutions were spotted onto various media indicated above each panel. The plates were incubated at 30°C for 2-5 d. The strain backgrounds are labeled on the left.