Use the universal genetic code wherever applicable to determ

Use the universal genetic code, wherever applicable, to determine amino acid sequence.                                                                        

ATG CTA GAG GTG TAA

1. Translate the DNA sequence to make a protein.

2. Show the effect of an insertion, deletion, and substitution on the sequence of DNA provided.

3. Which of the above mutations will result in a shift in the reading frame?

4. What type of substitution mutation (missense, silent, and non-sense) was introduced in your sequence?

Solution

1. The protein sequence has following amino acids according to the codes given in the question

Met-Leu-Glu-Val

2. Insertion- results in following sequence of codons

ATA-GCT-AGA-GGT-GTA which gives rise to the polypeptide with amino acids:

Isoleucine-Alanine-Arginine-Glycine-Valine

Deletion gives rise to following sequence

ATC-TAG-AGG-TGT resulting in only 1 amino acid:

Isoleucine

Substitution would result in the following sequence

ATG-CTC-GAG-GTG-TAA

Resulting in the polypeptide with amino acids

Methionine-Leucine-Glutamic acid-Valine

3. Insertion and deletion would result in the frame shift

4. The type of substitution introduced is the silent mutation because the initial as well the new sequence both code for the same amino acid leucine. Hence there is no change in the resulting polypeptide.