Practice question

Site-directed mutagenesis provides powerful reverse genetics approach to determine functionally critical residues within protein. By changing specific codon to encode alternate amino acid, mutant protein can be tested for loss of enzymatic catalysis, DNA binding, protein-protein interaction or stability. Comparing activity of wild-type versus mutant variants through biochemical assays or complementation studies identifies residues essential for active site geometry, allostery or post-translational modification. This targeted approach reveals structure-function relationships, validates computational predictions and guides drug design, unlike random fragmentation, exon mapping or simple sequencing applications.