Figure 1.

Schematic showing predicted position of the 40S ribosome terminating at the stop codon of uORF1 from the GCN4 mRNA leader. The E, P and A sites of the 40S ribosome are aligned with the last two coding triplets and the UAA stop codon; entry and exit pores of the mRNA binding channel are labeled. The locations of the uORF1 5′ enhancer containing four RPEs, the RPEs i. and iv. of which interact with the NTD of a/TIF32, linker and buried parts of the sequences upstream of uORF1, as well as the 3′ sequences are indicated. The interaction between the a/TIF32-NTD and the small ribosomal protein RPS0A is depicted by a double headed arrow (adapted from (12)).