Fig. 2. The N domain of Ski7p is necessary and sufficient for the 3′-to-5′ degradation of mRNA. Yeast strains MC046 (vector), MC047 (Ski7p/N), MC048 (Ski7p/C) and MC049 (Ski7p/Full), carrying the GAL1:MFA2pG reporter, were grown in a galactose-containing medium and harvested at the mid-log phase (OD₆₀₀ = 0.4–0.5). RNA extracted from the cells was subjected to polyacrylamide gel northern blot analysis as described in Materials and methods. Positions of the full-length and poly(G) (pG) to 3′-end fragments of MFA2pG mRNA are indicated on the left. ORF, open reading frame.