Figure I.

Three major types of recoding events. Read-through entails the insertion of an unusual amino acid (gold) at the position of a stop codon. Bypassing connects two parts of a discontinuous reading frame (green and blue linear segments) resulting in a single protein (green-blue). Frameshifting may be used to regulate the synthesis of a single protein or to produce two proteins (peptide ORF1 and peptide ORF1+2) from a single mRNA with two overlapping open reading frames (ORFS; green and blue segments). The black arrows indicate the direction of ribosome movement.