IES insertion within the coding sequence (CDS) potentially diversifies protein sequences. (A) Theoretical diversification potential of PGM-IESs. Pro-IES (green): fraction of 3n, non-PTC-inducing IESs (“productive” IESs). Tail-IES (crimson red): fraction of IESs that do not introduce a premature termination codon (PTC) but lead to the ablation of the true stop codon. FS-IES (orange): fraction of IESs that disrupt the open reading frame by introducing a downstream PTC owing to frameshift (FS). PTC-IES (red): fraction of IESs that introduces a PTC within the insertion. (B) Classification of the 146 within-CDS IES insertions observed at 32°C based on the predicted transcriptional outcome. The mean excision score (1-µIRS), mean IRS (µIRS), and maximum IRS (M) are indicated beside each category. The number of IESs is indicated within parentheses. The predicted effect on the protein products is depicted schematically next to each class.
