Three to One

Convert three letter amino acid codes to one letter codes

Tool Configuration
Configure the parameters for Three to One

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

1

Input Three-Letter Sequences

Paste protein sequences using three-letter amino acid codes (Ala, Cys, Asp, etc.). Input can be in any case and FASTA format is supported.

2

Execute Conversion

The tool automatically formats triplets to proper case and converts them to single-letter codes (e.g., Ala → A, Cys → C).

3

Review Compact Format

The converted sequences are displayed in compact single-letter format with 60 characters per line for easy reading.

4

Download for Further Use

Save the converted sequences for database submission, alignment tools, or any application requiring standard single-letter notation.

Use Cases
Common applications for the Three to One tool

Sequence Compaction

Convert verbose three-letter notation to compact single-letter format for easier viewing and analysis.

Database Submission

Prepare sequences for submission to databases that require single-letter amino acid notation.

Alignment Processing

Convert three-letter sequences to single-letter format for compatibility with alignment tools.

Format Standardization

Standardize protein sequence format from various sources that use three-letter codes.

Amino Acid Code Conversion

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

Processing Notes

Automatic Formatting: The tool automatically formats triplets to proper case (first letter uppercase, rest lowercase) before conversion.
Whitespace Removal: Digits and blank spaces are automatically removed from the input.
Non-standard Triplets: Triplets that don't match standard amino acid codes are ignored and left as-is.
Case Insensitive: Input can be in any case (ALA, Ala, ala will all be converted to A).