The first step in sequencing of DNA into a protein is called transcription. Transcription refers to transcribing a strand of DNA to a single strand of messenger rNA or mRNA. The mRNA is then modified (removal of introns, splicing of exons, adding the 5' cap and the poly-A tail, etc) then transported to the nucleus. The second step is called translation. Translation is refers to translating the mRNA strand into its corresponding amino acid based on codon sequences.