Open reading frame

An open reading frame (ORF) is a sequence of DNA that has the potential to be translated into a protein. It is defined as a continuous stretch of nucleotides that begins with a start codon (usually AUG) and ends with a stop codon (either UAA, UAG, or UGA) without any intervening stop codons. The presence of an ORF suggests that the corresponding RNA transcript can be translated into a polypeptide chain.