Q. The sequence of the cloned DNA and the amino acids encoded by open reading frames. Stop codons are underlined and labelled 2 or 3 to indicate their reading frame. As you can appreciate from this exercise, sequencing gel must be read very carefully; omission of a single nucleotide would have disastrous consequences for determining the open reading frame. As you can appreciate the in-frame amino acid sequence represents an internal portion of the protein. The sequence encodes the canine SRP receptor.