Reading frame

In molecular biology, a reading frame is a way of dividing the sequence of nucleotides in a nucleic acid (DNA or RNA) molecule into a set of consecutive, non-overlapping triplets.

A single strand of a nucleic acid molecule has a phosphoryl end, called the 5′-end, and a hydroxyl or 3′-end.

The codons of the mRNA reading frame are translated in the 5′→3′ direction into amino acids by a ribosome to produce a polypeptide chain.

[5] The usage of multiple reading frames leads to the possibility of overlapping genes; there may be many of these in viral, prokaryote, and mitochondrial genomes.

This is distinct from a frameshift mutation, as the nucleotide sequence (DNA or RNA) is not altered—only the frame in which it is read.