Mutate Protein introduces residue changes into a protein sequence. You can select the number of mutations to introduce, and whether or not to preserve the first residue in the sequence, to reflect selection acting to maintain a start codon. The position of each mutation is chosen randomly, and multiple mutations can occur at a single site. Mutated sequences can be used to evaluate the significance of sequence analysis results.
Reference:
P. Stothard. The sequence manipulation suite: JavaScript programs for analyzing and formatting protein and DNA sequences. Biotechniques 2000; 28: 1102, 1104.