## DNA_and_amino_acids_nomenclature

### DNA

    G       Guanine
    A       Adenine
    T       Thymine
    C       Cytosine
    R       Purine                  A,G
    Y       Pyrimidine              T,C
    M       Amino                   A,C
    K       Ketone                  G,T
    S       Strong interaction      C,G
    W       Weak interaction        A,T
    H       not-G                   A,C,T
    B       not-A                   G,C,T
    V       not-T                   A,C,G
    D       not-C                   A,G,T
    N       any                     G,A,T,C

### Amino Acids

Here is a list of the standard one-letter amino acid codes and their three-letter equivalents. The synonymous codons and their depiction in the IUB codes are shown. You should recognize that the codons following semicolons (;) are not sufficiently specific to define a single amino acid even though they represent the best possible back translation into the IUB codes! All of the relationships in this list can be redefined by the user in a local data file described below.

    mbol 3-letter  Meaning      Codons                Depiction

    A    Ala       Alanine      GCT,GCC,GCA,GCG         !GCN
    B    Asp,Asn   Aspartic,
                   Asparagine   GAT,GAC,AAT,AAC         !RAY
    C    Cys       Cysteine     TGT,TGC                 !TGY
    D    Asp       Aspartic     GAT,GAC                 !GAY
    E    Glu       Glutamic     GAA,GAG                 !GAR
    F    Phe     Phenylalanine  TTT,TTC                 !TTY
    G    Gly       Glycine      GGT,GGC,GGA,GGG         !GGN
    H    His       Histidine    CAT,CAC                 !CAY
    I    Ile       Isoleucine   ATT,ATC,ATA             !ATH
    K    Lys       Lysine       AAA,AAG                 !AAR
    L    Leu       Leucine      TTG,TTA,CTT,CTC,CTA,CTG !TTR,CTN,YTR;YTN
    M    Met       Methionine   ATG                     !ATG
    N    Asn       Asparagine   AAT,AAC                 !AAY
    P    Pro       Proline      CCT,CCC,CCA,CCG         !CCX
    Q    Gln       Glutamine    CAA,CAG                 !CAR
    R    Arg       Arginine     CGT,CGC,CGA,CGG,AGA,AGG !CGX,AGR,MGR;MGN
    S    Ser       Serine       TCT,TCC,TCA,TCG,AGT,AGC !TCX,AGY;WSN
    T    Thr       Threonine    ACT,ACC,ACA,ACG         !ACN
    V    Val       Valine       GTT,GTC,GTA,GTG         !GTN
    W    Trp       Tryptophan   TGG                     !TGG
    X    Xxx       Unknown                              !NNN
    Y    Tyr       Tyrosine     TAT, TAC                !TAY
    Z    Glu,Gln   Glutamic,
                   Glutamine    GAA,GAG,CAA,CAG         !SAR
    *    End       Terminator   TAA, TAG, TGA           !TAR,TRA;TRR

to Table of Contents

last edited: July 1994