If a mutation changes the RNA three-letter code from UAU to UAA in one location, the result will be: changing several amino acids in the protein no change in the amino acid shortening of the protein because of the STOP signal a change to a different amino acid DNA-dependent RNA polymerase is found in: cells and some viruses cells cells and all viruses some viruses all viruses changing several amino acids in the protein no change in the amino acid shortening of the protein because of the STOP signal a change to a different amino acid.