Amino Acid Codes
The standard, single-letter amino acid codes are used when specifying a protein sequence in FASTA Format or when entering the data for a protein-based BLAST search. They are given below, along with the three-letter abbreviations and the three-nucleotide sequences (codons) that produce them. For nucleotide codes, see DNA Nucleotide Code.| Code | Abbreviation | Name | Codons | Notes |
|---|---|---|---|---|
| A | ala | Alanine | GCT, GCC, GCA, GCG | |
| C | cys | Cysteine | TGT, TGC | |
| D | asp | Aspartic acid | GAT, GAC | |
| E | glu | Glutamic acid | GAA, GAG | |
| F | phe | Phenylalanine | TTT, TTC | |
| G | gly | Glycine | GGT, GGC, GGA, GGG | |
| H | his | Histidine | CAT, CAC | |
| I | ile | Isoleucine | ATT, ATC, ATA | |
| K | lys | Lysine | AAA, AAG | |
| L | leu | Leucine | TTA, TTG, CTT, CTC, CTA, CTG | |
| M | met | Methionine | ATG | Methionine is usually the first amino acid of a protein. It is also produced by TTG and GTG when they appear as a start codon. |
| N | asn | Asparagine | AAT, AAC | |
| P | pro | Proline | CCT, CCC, CCA, CCG | |
| Q | glu | Glutamine | CAA, CAG | |
| R | arg | Arginine | CGT, CGC, CGA, CGG, AGA, AGG | |
| S | ser | Serine | TCT, TCC, TCA, TCG, AGT, AGC | |
| T | thr | Threonine | ACT, ACC, ACA, ACG | |
| V | val | Valine | GTT, GTC, GTA, GTG | |
| W | trp | Tryptophan | TGG | In Mycoplasma, tryptophan is also produced by TGA |
| Y | tyr | Tyrosine | TAT, TAC | |
| * | Stop Codon | TAA, TAG, TGA | The stop codon does not produce an amino acid. |
| SequencingForm | |
|---|---|
| Sequence | 000010Am |
| Summary | Standard entry codes for protein sequences |
Topic revision: r8 - 04 Mar 2009 - 18:22:37 - Leslie Mc Neil
Notice to NMPDR Users - The NMPDR BRC contract has ended and bacterial data from NMPDR has been transferred to PATRIC (http://www.patricbrc.org), a new consolidated BRC for all NIAID category A-C priority pathogenic bacteria. NMPDR was a collaboration among researchers from the Computation Institute of the University of Chicago, the Fellowship for Interpretation of Genomes (FIG), Argonne National Laboratory, and the National Center for Supercomputing Applications (NCSA) at the University of Illinois. NMPDR is funded by the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Department of Health and Human Services, under Contract HHSN266200400042C. Banner images are copyright © Dennis Kunkel.