Every DNA strand has six possible reading frames, three on the sense strand going in the forward direction and three on the anti-sense strand that goes in the reverse direction. The start codon for the open reading frame is ATG, which codes for Methionine, whereas the stop codons are TAA, TAG and TGA.
Identifying open reading frames can be tricky as even though there are many stop codons, it is not always possible to identify the correct one. As a result, we can not always be sure how long an open reading frame is, making it hard to pick them out and identify a protein.
- ↑ Alberts, et al. Molecular Biology of the Cell. 5th ed. Garland Science. 2008