Site-directed mutagenesis is 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 a particular asparagine (an amino acid) within a protein you are studying. Using site-directed mutagenesis, you make mutant proteins in which this asparagine has been changed to other amino acids. You then test the encoded mutant proteins for functionality. The results are as follows:

From these results, what would you conclude about the functional significance of this asparagine within the protein?

Wild-type (normal) protein Mutant proteins containing Leucine Phenylalanine Glutamine Proline Functionality (%) 100 7304 98