One to Three

Convert single letter amino acid codes to three letter codes

Tool Configuration
Configure the parameters for One to Three

Paste the raw sequence or one or more FASTA sequences. Input limit is 100,000,000 characters.

1

Prepare Your Protein Sequences

Paste your protein sequences in FASTA format or as raw sequences. The tool accepts single-letter amino acid codes (A, C, D, E, etc.).

2

Execute the Conversion

Click the execute button to convert all single-letter amino acid codes to their three-letter equivalents (e.g., A → Ala, C → Cys).

3

Review the Results

The converted sequences are formatted with proper capitalization (first letter uppercase, rest lowercase) and line breaks every 60 characters.

4

Download or Copy

Use the download button to save the results as a text file, or copy the output for use in publications or presentations.

Use Cases
Common applications for the One to Three tool

Publication Formatting

Convert sequences to three-letter codes for formal publications and scientific documentation.

Sequence Presentation

Improve readability of protein sequences in presentations and educational materials.

Structural Biology

Prepare sequences for structural analysis tools that require three-letter amino acid codes.

Database Submission

Format sequences for databases or applications that specifically require three-letter notation.

Amino Acid Code Reference

A → Ala (Alanine)
C → Cys (Cysteine)
D → Asp (Aspartate)
E → Glu (Glutamate)
F → Phe (Phenylalanine)
G → Gly (Glycine)
H → His (Histidine)
I → Ile (Isoleucine)
K → Lys (Lysine)
L → Leu (Leucine)
M → Met (Methionine)
N → Asn (Asparagine)
P → Pro (Proline)
Q → Gln (Glutamine)
R → Arg (Arginine)
S → Ser (Serine)
T → Thr (Threonine)
V → Val (Valine)
W → Trp (Tryptophan)
Y → Tyr (Tyrosine)
B → Asx (Asp/Asn)
Z → Glx (Glu/Gln)
X → Xaa (Unknown)
* → *** (Stop)