Translational helicases Ded1 and Slh1 are not essential for 40S scanning. GFP fluorescence measured in mutant strains normalized to respective GFP fluorescence in the wild-type (BY4741) strain. Error bars indicate standard deviations determined from three biological replicates. (A) NUS1 RNA-ID constructs were transformed into a ded1-120 strain containing cold-sensitive allele ded1-120, which encodes the mutant form of Ded1 helicase bearing the amino acid substitutions G108D and G494D. (B) NUS1 RNA-ID constructs were transformed into the slh1Δ or asc1Δ strains, helicase Slh1 and ribosomal protein Asc1, respectively. In A, GFP synthesis was induced concurrently with the temperature shift from 30°C to 18°C.
