Amino acid symbols: Symbols that stand for the amino acids, the building blocks of protein. Each amino acid has both a three-letter symbol and a single-letter symbol. For example, the three-letter and single-letter symbols for alanine are Ala and A. The three-letter symbols (such as Ala) are much more widely used than the single letter ones (such as A).
Therefore, the following list is limited to the three-letter symbols and is further limited to those 20 alpha-amino acids specified by the genetic code:
These three-letter symbols for amino acids are used not only to refer to an individual amino acid but also to present the amino acid sequence of a polypeptide or a protein. For example, part of the sequence of insulin reads: Gly-Ile-Val-Glu-Gln-Cys-Cys-Ala-Ser-Val. The N-terminal residue of the polypeptide or protein is by convention always on the left and the sequence reads from left-to-right toward the C-terminal residue of the polypeptide or protein.
Amino acid : One letter symbol: Three letter symbol: alanine : A : Ala : arginine : R : Arg: asparagine : N : Asn: aspartic acid : D : Asp: cysteine : C : Cys: glutamic acid : E : Glu
The symbols are listed, in alphabetical order of amino-acid names, in Table 1. Table 5 gives them in alphabetical order of symbols. Table 5. The One-Letter Symbols
A table listing amino acid symbols including one-letter symbols, three-letter symbols, IUPAC nomenclature and corresponding codons of the standard amino acids.
Amino acid symbols: Symbols that stand for the amino acids, the building blocks of protein. Each amino acid has both a three-letter symbol and a single-letter symbol.
Amino acids: Symbols: Codons: Alanine: Ala: A: GCA, GCC, GCG, GCU: Cysteine: Cys: C: UGC, UGU: Aspartic acid: Asp: D: GAC, GAU: Glutamic acid: Glu: E: GAA, GAG: Phenylalanine: Phe: F: UUC, UUU