Amino Acid Code Converter
Switch between compact one-letter protein notation and readable three-letter residue codes. Choose the input notation explicitly, then copy the converted sequence. The converter reports ambiguous, unknown, and unsupported codes at their positions in the original input.
Results
Convert valid codes to see the result.
How amino acid codes are converted
Each standard residue has one entry in the IUPAC–IUBMB mapping. One-letter input can be continuous or wrapped. Separate three-letter input with whitespace. Output uses uppercase one-letter codes or space-separated three-letter codes in standard case.
Read the calculation method →Worked example
ACD
ACD converts to Ala Cys Asp. In the reverse direction, Ala Cys Asp converts to ACD.
Limitations
- Conversion accepts the 20 standard amino acids. Ambiguous and unknown codes, uncommon amino acids outside this alphabet, and punctuation produce explicit errors.
- Resolve every issue before copying converted output. The original text is preserved.