Table 1.
Amino acid replacement scheme
| Residue | Codon | Replacement | Codon |
| Ala | GCN | Gly | GGN |
| Asp | GAY | Asn | AAY |
| Glu | GAR | Gln | CAR |
| Phe | TTY | Tyr | TAY |
| Gly | GGN | Ala | GCN |
| His | CAY | Asn | AAY |
| Ile | ATH | Leu | CTH |
| Lys | AAR | Arg | AGR |
| Leu | CTH | Ile | ATH |
| TTR | ATR | ||
| Met | ATG | Leu | CTG |
| Asn | AAY | Asp | GAY |
| Pro | CCN | Ala | GCN |
| Gln | CAR | Glu | GAR |
| Arg | AGR | Lys | AAR |
| Ser | TCN | Thr | ACN |
| AGY | ACY | ||
| Thr | ACN | Ser | TCN |
| Val | GTN | Leu | CTN |
| Trp | TGG | Leu | TTG |
| Tyr | TAY | Phe | TTY |
Amino acids were mutated to the closest homologs that can be reached with only one base change. Codons used are shown above, with relevant degeneracies indicated with IUPAC nomenclature (N = A/C/G/T; Y = C/T; R = A/G; H = A/C/T). Changed base is indicated in bold. Cysteine is not shown, as there are no cysteines in the P99 enzyme.