FIGURE 5.

The 7-repeats and NTD are required, but the RRM is dispensable, for full complementation of the tif3Δ growth defect. (A,B) 10-fold serial dilutions of transformants of tif3Δ strain FJZ052 harboring sc or hc plasmids with the indicated TIF3 alleles or empty vector were spotted on SC-Leu medium and incubated for 4 d at 18°C. Growth was scored from 0 (empty vector) to 10 (TIF3⁺) based on colony size and highest dilution where colonies appeared, and reported as complementation (comp’n) of tif3Δ. (C) WCEs prepared under denaturing conditions from strains in A and B were subjected to Western analysis with antibodies against His₆ epitope (to visualize Tif3-His₆ proteins) or an eIF2B subunit (Gcd6) as loading control. Intensities of Tif3-His₆ signals relative to Gcd6 were normalized to those for sc TIF3⁺ transformants. Mean and standard errors calculated from replicate determinations are listed under “Protein level” in A and B. (na) Not applicable.