Question

#You have the sequence 5' AUG AAG UUC UGA. Write the corresponding polypeptide

              Now do the following operations:

              a) change any one nucleotide (type it in bold face)

              b) add a single nucleotide at any position to the original sequence (again type it in bold face)

              c) remove a single nucleotide at any position to the original sequence (again type it in bold face)

              write down the corresponding polypeptides.

              Which change(s) affected the polypeptide sequence the most?

Answer 1

Substitution of a single nuleotide by another nucleotide leads to a change in single amino acid, encoded by that specific codon where the change was involved.

Whereas, addition or deletion of a nucleotide leads to the frameshift mutation which changes the entire reading frame, starting from the position where the change was involved. Hence, it tends to be more deleterious and affects the polypeptide sequences the most.