Genetics: Analysis and Principles 5th Edition by Robert Brooker

Exercise 49

Site-directed mutagenesis is also used to explore the structure and function of proteins. For example, changes can be made to the coding sequence of a gene to determine how alterations in the amino acid sequence affect the function of a protein. Let's suppose that you are interested in the functional importance of one glutamic acid residue within a protein you are studying. By site-directed mutagenesis, you make mutant proteins in which this glutamic acid codon has been changed to other codons. You then test the encoded mutant proteins for functionality. The results are as follows:

a.
From these results, what would you conclude about the functional significance of the glutamic acid residue within the protein