Question

As part of your new job at Genes R Us, you have been asked to work with the DNA coding sequence below and provide information to the vice president in charge of new projects. Given that the sequence below is in frame (meaning that the first nucleotide is the first nucleotide of a codon) and that the sequence is coding sequence, answer the following questions. (see final page for assistance).  

GCA-AGU-GAC-CAG-UGC-CUG-AAA-GAG-CAG-UCU

a) What peptide would be produced from this sequence?

b) Assuming that this sequence is near the beginning of a gene, what nucleotide could you mutate to create the most dramatic change in the final protein product? (Note that deletions or insertions are not allowed). Explain your answer.

Answer 1

Q1 )

Alanine - Serine - Aspartate - glutamine - Cysteine - leucine - Lysine - glutamate - glutamine - Serine.

Each triplet codon codes for a corresponding amino acid. The amino acid sequence mentioned above is corresponding to the respective codons from the beginning.

Q2) Cytosine to Adenine in the fifth codon UGC to UGA.

UGA is a stop codon, there for if UGC is mutated to UGA the protein synthesis will stop there leading to the production of a truncated protein which is the most dramatic change in the final protein product.