Figure 3 .

The β-ring of the proteasome core particle enhances cellular fitness during fermentation. The proteasome core particle α-ring (α1-7) and β-ring subunits (β1-7) are shown, along with the Irc25/Poc4 α-ring assembly chaperone. The proteasome regulatory particle (base and lid subunits) is also shown. Genes are color coded as follows: green, reduced fitness; red, increased fitness; black, no change in fitness; gray, no data obtained.