DNA and RNA codon tables

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A circular diagram is separated into three rings, broken down into sections labeled with the letters: G, U, A, and C. Each represents a nucleotide found in RNA. The center ring is divided into four areas marked with a unique letter. The second ring is divided into 16 sections also labeled with a nucleotide. They are organized so that the outer edge of the central letters touches four unique nucleotides. The third outer ring, divided into 64 sections labeled with a nucleotide, repeats this. Amino acids are placed outside of the circular diagram and are in contact with specific nucleotides. Using this diagram, one can connect a sequence of three nucleotides with a specific amino acid. For example, given "GUC", one can follow contigous sections of the rings from the center to the outside: from G to U and U to C. This leads the user to the amino acid Alanine.
The standard RNA codon table organized in a wheel
A double helix is situated horizontally. The helix contains vertical letter pairs (e.g. G & C, C & G, and A & T) that represent the base pairs within DNA. The bottom letter of each pair is written below the helix. These letters are in groups of three (triplets). Beneath each triplet is an arrow pointing to the corresponding amino acid. For example, an arrow points from "GCA" to Alanine.
The three consecutive DNA bases, called nucleotide triplets or codons, are translated into amino acids (GCA to alanine, AGA to arginine, GAT to aspartic acid, AAT to asparagine, and TGT to cysteine in this example).

A codon table can be used to translate a genetic code into a sequence of amino acids.[1][2] The standard genetic code is traditionally represented as an RNA codon table, because when proteins are made in a cell by ribosomes, it is messenger RNA (mRNA) that directs protein synthesis.[2][3] The mRNA sequence is determined by the sequence of genomic DNA.[4] In this context, the standard genetic code is referred to as translation table 1.[3] It can also be represented in a DNA codon table. The DNA codons in such tables occur on the sense DNA strand and are arranged in a 5′-to-3′ direction. Different tables with alternate codons are used depending on the source of the genetic code, such as from a cell nucleus, mitochondrion, plastid, or hydrogenosome.[5]

There are 64 different codons in the genetic code and the below tables; most specify an amino acid.[6] Three sequences, UAG, UGA, and UAA, known as stop codons,[note 1] do not code for an amino acid but instead signal the release of the nascent polypeptide from the ribosome.[7] In the standard code, the sequence AUG—read as methionine—can serve as a start codon and, along with sequences such as an initiation factor, initiates translation.[3][8][9] In rare instances, start codons in the standard code may also include GUG or UUG; these codons normally represent valine and leucine, respectively, but as start codons they are translated as methionine or formylmethionine.[3][9]

The first table—the standard table—can be used to translate nucleotide triplets into the corresponding amino acid or appropriate signal if it is a start or stop codon. The second table, appropriately called the inverse, does the opposite: it can be used to deduce a possible triplet code if the amino acid is known. As multiple codons can code for the same amino acid, the International Union of Pure and Applied Chemistry's (IUPAC) nucleic acid notation is given in some instances.

Translation table 1[edit]

Standard RNA codon table[edit]

Amino-acid biochemical properties Nonpolar Up-arrow Polar dagger Basic double-dagger Acidic ↓ Termination: stop codon * Initiation: possible start codon →
Standard genetic code[1][10]
1st
base
2nd base 3rd
base
U C A G
U UUU (Phe/F) Phenylalanine Up-arrow UCU (Ser/S) Serine dagger UAU (Tyr/Y) Tyrosine dagger UGU (Cys/C) Cysteine dagger U
UUC UCC UAC UGC C
UUA (Leu/L) Leucine Up-arrow UCA UAA Stop (Ochre) *[note 2] UGA Stop (Opal) *[note 2] A
UUG → UCG UAG Stop (Amber) *[note 2] UGG (Trp/W) Tryptophan Up-arrow G
C CUU CCU (Pro/P) Proline Up-arrow CAU (His/H) Histidine double-dagger CGU (Arg/R) Arginine double-dagger U
CUC CCC CAC CGC C
CUA CCA CAA (Gln/Q) Glutamine dagger CGA A
CUG CCG CAG CGG G
A AUU (Ile/I) Isoleucine Up-arrow ACU (Thr/T) Threonine dagger AAU (Asn/N) Asparagine dagger AGU (Ser/S) Serine dagger U
AUC ACC AAC AGC C
AUA ACA AAA (Lys/K) Lysine double-dagger AGA (Arg/R) Arginine double-dagger A
AUG → (Met/M) Methionine Up-arrow ACG AAG AGG G
G GUU (Val/V) Valine Up-arrow GCU (Ala/A) Alanine Up-arrow GAU (Asp/D) Aspartic acid GGU (Gly/G) Glycine Up-arrow U
GUC GCC GAC GGC C
GUA GCA GAA (Glu/E) Glutamic acid GGA A
GUG → GCG GAG GGG G

Inverse RNA codon table[edit]

Inverse table for the standard genetic code (compressed using IUPAC notation)[13]
Amino acid RNA codons Compressed Amino acid RNA codons Compressed
Ala, A GCU, GCC, GCA, GCG GCN Ile, I AUU, AUC, AUA AUH
Arg, R CGU, CGC, CGA, CGG; AGA, AGG CGN, AGR; or
CGY, MGR
Leu, L CUU, CUC, CUA, CUG; UUA, UUG CUN, UUR; or
CUY, YUR
Asn, N AAU, AAC AAY Lys, K AAA, AAG AAR
Asp, D GAU, GAC GAY Met, M AUG
Asn or Asp, B AAU, AAC; GAU, GAC RAY Phe, F UUU, UUC UUY
Cys, C UGU, UGC UGY Pro, P CCU, CCC, CCA, CCG CCN
Gln, Q CAA, CAG CAR Ser, S UCU, UCC, UCA, UCG; AGU, AGC UCN, AGY
Glu, E GAA, GAG GAR Thr, T ACU, ACC, ACA, ACG ACN
Gln or Glu, Z CAA, CAG; GAA, GAG SAR Trp, W UGG
Gly, G GGU, GGC, GGA, GGG GGN Tyr, Y UAU, UAC UAY
His, H CAU, CAC CAY Val, V GUU, GUC, GUA, GUG GUN
START AUG STOP UAA, UGA, UAG URA, UAR

Standard DNA codon table[edit]

Amino-acid biochemical properties Nonpolar Up-arrow Polar dagger Basic double-dagger Acidic ↓ Termination: stop codon * Initiation: possible start codon →
Standard genetic code[14][note 3]
1st
base
2nd base 3rd
base
T C A G
T TTT (Phe/F) Phenylalanine Up-arrow TCT (Ser/S) Serine dagger TAT (Tyr/Y) Tyrosine dagger TGT (Cys/C) Cysteine dagger T
TTC TCC TAC TGC C
TTA (Leu/L) Leucine Up-arrow TCA TAA Stop (Ochre) *[note 2] TGA Stop (Opal) *[note 2] A
TTG → TCG TAG Stop (Amber) *[note 2] TGG (Trp/W) Tryptophan Up-arrow G
C CTT CCT (Pro/P) Proline Up-arrow CAT (His/H) Histidine double-dagger CGT (Arg/R) Arginine double-dagger T
CTC CCC CAC CGC C
CTA CCA CAA (Gln/Q) Glutamine dagger CGA A
CTG CCG CAG CGG G
A ATT (Ile/I) Isoleucine Up-arrow ACT (Thr/T) Threonine dagger AAT (Asn/N) Asparagine dagger AGT (Ser/S) Serine dagger T
ATC ACC AAC AGC C
ATA ACA AAA (Lys/K) Lysine double-dagger AGA (Arg/R) Arginine double-dagger A
ATG → (Met/M) Methionine Up-arrow ACG AAG AGG G
G GTT (Val/V) Valine Up-arrow GCT (Ala/A) Alanine Up-arrow GAT (Asp/D) Aspartic acid GGT (Gly/G) Glycine Up-arrow T
GTC GCC GAC GGC C
GTA GCA GAA (Glu/E) Glutamic acid GGA A
GTG → GCG GAG GGG G

Inverse DNA codon table[edit]

Inverse table for the standard genetic code (compressed using IUPAC notation)[13]
Amino acid DNA codons Compressed Amino acid DNA codons Compressed
Ala, A GCT, GCC, GCA, GCG GCN Ile, I ATT, ATC, ATA ATH
Arg, R CGT, CGC, CGA, CGG; AGA, AGG CGN, AGR; or
CGY, MGR
Leu, L CTT, CTC, CTA, CTG; TTA, TTG CTN, TTR; or
CTY, YTR
Asn, N AAT, AAC AAY Lys, K AAA, AAG AAR
Asp, D GAT, GAC GAY Met, M ATG
Asn or Asp, B AAT, AAC; GAT, GAC RAY Phe, F TTT, TTC TTY
Cys, C TGT, TGC TGY Pro, P CCT, CCC, CCA, CCG CCN
Gln, Q CAA, CAG CAR Ser, S TCT, TCC, TCA, TCG; AGT, AGC TCN, AGY
Glu, E GAA, GAG GAR Thr, T ACT, ACC, ACA, ACG ACN
Gln or Glu, Z CAA, CAG; GAA, GAG SAR Trp, W TGG
Gly, G GGT, GGC, GGA, GGG GGN Tyr, Y TAT, TAC TAY
His, H CAT, CAC CAY Val, V GTT, GTC, GTA, GTG GTN
START ATG STOP TAA, TGA, TAG TRA, TAR

Alternative codons in other translation tables[edit]

The genetic code was once believed to be universal:[16] a codon would code for the same amino acid regardless of the organism or source. However, it is now agreed that the genetic code evolves,[17] resulting in discrepancies in how a codon is translated depending on the genetic source.[16][17] For example, in 1981, it was discovered that the use of codons AUA, UGA, AGA and AGG by the coding system in mammalian mitochondria differed from the universal code.[16] Stop codons can also be affected: in ciliated protozoa, the universal stop codons UAA and UAG code for glutamine.[17][note 4] The following table displays these alternative codons.

Amino-acid biochemical properties Nonpolar Up-arrow Polar dagger Basic double-dagger Acidic ↓ Termination: stop codon *
Comparison between codon translations with alternative and standard genetic codes[3]
Code Translation
table
DNA codon involved RNA codon involved Translation
with this code
Standard translation Notes
Standard 1 Includes translation table 8 (plant chloroplasts).
Vertebrate mitochondrial 2 AGA AGA Stop * Arg (R) double-dagger
AGG AGG Stop * Arg (R) double-dagger
ATA AUA Met (M) Up-arrow Ile (I) Up-arrow
TGA UGA Trp (W) Up-arrow Stop *
Yeast mitochondrial 3 ATA AUA Met (M) Up-arrow Ile (I) Up-arrow
CTT CUU Thr (T) dagger Leu (L) Up-arrow
CTC CUC Thr (T) dagger Leu (L) Up-arrow
CTA CUA Thr (T) dagger Leu (L) Up-arrow
CTG CUG Thr (T) dagger Leu (L) Up-arrow
TGA UGA Trp (W) Up-arrow Stop *
CGA CGA absent Arg (R) double-dagger
CGC CGC absent Arg (R) double-dagger
Mold, protozoan, and coelenterate mitochondrial + Mycoplasma / Spiroplasma 4 TGA UGA Trp (W) Up-arrow Stop * Includes the translation table 7 (kinetoplasts).
Invertebrate mitochondrial 5 AGA AGA Ser (S) dagger Arg (R) double-dagger
AGG AGG Ser (S) dagger Arg (R) double-dagger
ATA AUA Met (M) Up-arrow Ile (I) Up-arrow
TGA UGA Trp (W) Up-arrow Stop *
Ciliate, dasycladacean and Hexamita nuclear 6 TAA UAA Gln (Q) dagger Stop *
TAG UAG Gln (Q) dagger Stop *
Echinoderm and flatworm mitochondrial 9 AAA AAA Asn (N) dagger Lys (K) double-dagger
AGA AGA Ser (S) dagger Arg (R) double-dagger
AGG AGG Ser (S) dagger Arg (R) double-dagger
TGA UGA Trp (W) Up-arrow Stop *
Euplotid nuclear 10 TGA UGA Cys (C) dagger Stop *
Bacterial, archaeal and plant plastid 11 See translation table 1.
Alternative yeast nuclear 12 CTG CUG Ser (S) dagger Leu (L) Up-arrow
Ascidian mitochondrial 13 AGA AGA Gly (G) Up-arrow Arg (R) double-dagger
AGG AGG Gly (G) Up-arrow Arg (R) double-dagger
ATA AUA Met (M) Up-arrow Ile (I) Up-arrow
TGA UGA Trp (W) Up-arrow Stop *
Alternative flatworm mitochondrial 14 AAA AAA Asn (N) dagger Lys (K) double-dagger
AGA AGA Ser (S) dagger Arg (R) double-dagger
AGG AGG Ser (S) dagger Arg (R) double-dagger
TAA UAA Tyr (Y) dagger Stop *
TGA UGA Trp (W) Up-arrow Stop *
Blepharisma nuclear 15 TAG UAG Gln (Q) dagger Stop * As of Nov. 18, 2016: absent from the NCBI update. Similar to translation table 6.
Chlorophycean mitochondrial 16 TAG UAG Leu (L) Up-arrow Stop *
Trematode mitochondrial 21 TGA UGA Trp (W) Up-arrow Stop *
ATA AUA Met (M) Up-arrow Ile (I) Up-arrow
AGA AGA Ser (S) Arg (R) double-dagger
AGG AGG Ser (S) dagger Arg (R) double-dagger
AAA AAA Asn (N) dagger Lys (K) double-dagger
Scenedesmus obliquus mitochondrial 22 TCA UCA Stop * Ser (S) dagger
TAG UAG Leu (L) Up-arrow Stop *
Thraustochytrium mitochondrial 23 TTA UUA Stop * Leu (L) Up-arrow Similar to translation table 11.
Pterobranchia mitochondrial 24 AGA AGA Ser (S) dagger Arg (R) double-dagger
AGG AGG Lys (K) double-dagger Arg (R) double-dagger
TGA UGA Trp (W) Up-arrow Stop *
Candidate division SR1 and Gracilibacteria 25 TGA UGA Gly (G) Up-arrow Stop *
Pachysolen tannophilus nuclear 26 CTG CUG Ala (A) Up-arrow Leu (L) Up-arrow
Karyorelict nuclear 27 TAA UAA Gln (Q) dagger Stop *
TAG UAG Gln (Q) dagger Stop *
TG UGA Stop * or Trp (W) Up-arrow Stop *
Condylostoma nuclear 28 TAA UAA Stop * or Gln (Q) dagger Stop *
TAG UAG Stop * or Gln (Q) dagger Stop *
TGA UGA Stop * or Trp (W) Up-arrow Stop *
Mesodinium nuclear 29 TAA UAA Tyr (Y) dagger Stop *
TAG UAG Tyr (Y) dagger Stop *
Peritrich nuclear 30 TA UAA Glu (E) ↓ Stop *
TAG UAG Glu (E) ↓ Stop *
Blastocrithidia nuclear 31 TAA UAA Stop * or Glu (E) ↓ Stop *
TAG UAG Stop * or Glu (E) ↓ Stop *
TGA UGA Trp (W) Up-arrow Stop *
Cephalodiscidae mitochondrial code 33 AGA AGA Ser (S) dagger Arg (R) double-dagger Similar to translation table 24.
AGG AGG Lys (K) double-dagger Arg (R) double-dagger
TAA UAA Tyr (Y) dagger Stop *
TGA UGA Trp (W) Up-arrow Stop *

See also[edit]

Notes[edit]

  1. ^ Each stop codon has a specific name: UAG is amber, UGA is opal or umber, and UAA is ochre.[7] In DNA, these stop codons are TAG, TGA, and TAA, respectively.
  2. ^ a b c d e f The historical basis for designating the stop codons as amber, ochre and opal is described in the autobiography of Sydney Brenner[11] and in a historical article by Bob Edgar.[12]
  3. ^ The major difference between DNA and RNA is that thymine (T) is only found in the former. In RNA, it is replaced with uracil (U).[15] This is the only difference between the standard RNA codon table and the standard DNA codon table.
  4. ^ Euplotes octacarinatus is an exception.[17]

References[edit]

  1. ^ a b "Amino Acid Translation Table". Oregon State University. Archived from the original on 29 May 2020. Retrieved 2 December 2020.
  2. ^ a b Bartee, Lisa; Brook, Jack. MHCC Biology 112: Biology for Health Professions. Open Oregon. p. 42. Archived from the original on 6 December 2020. Retrieved 6 December 2020.
  3. ^ a b c d e Elzanowski A, Ostell J (7 January 2019). "The Genetic Codes". National Center for Biotechnology Information. Archived from the original on 9 October 2020. Retrieved 21 February 2019.
  4. ^ "RNA Functions". Scitable. Nature Education. Archived from the original on 18 October 2008. Retrieved 5 January 2021.
  5. ^ "The Genetic Codes". National Center for Biotechnology Information. Archived from the original on 13 May 2011. Retrieved 2 December 2020.
  6. ^ "Codon". National Human Genome Research Institute. Archived from the original on 22 October 2020. Retrieved 10 October 2020.
  7. ^ a b Maloy S. (29 November 2003). "How nonsense mutations got their names". Microbial Genetics Course. San Diego State University. Archived from the original on 23 September 2020. Retrieved 10 October 2020.
  8. ^ Hinnebusch AG (2011). "Molecular Mechanism of Scanning and Start Codon Selection in Eukaryotes". Microbiology and Molecular Biology Reviews. 75 (3): 434–467. doi:10.1128/MMBR.00008-11. PMC 3165540. PMID 21885680.
  9. ^ a b Touriol C, Bornes S, Bonnal S, Audigier S, Prats H, Prats AC, Vagner S (2003). "Generation of protein isoform diversity by alternative initiation of translation at non-AUG codons". Biology of the Cell. 95 (3–4): 169–78. doi:10.1016/S0248-4900(03)00033-9. PMID 12867081.
  10. ^ "The Information in DNA Determines Cellular Function via Translation". Scitable. Nature Education. Archived from the original on 23 September 2017. Retrieved 5 December 2020.
  11. ^ Brenner, Sydney; Wolpert, Lewis (2001). A Life in Science. Biomed Central Limited. p. 101–104. ISBN 9780954027803.
  12. ^ Edgar B (2004). "The genome of bacteriophage T4: an archeological dig". Genetics. 168 (2): 575–82. doi:10.1093/genetics/168.2.575. PMC 1448817. PMID 15514035. see pages 580–581
  13. ^ a b IUPAC—IUB Commission on Biochemical Nomenclature. "Abbreviations and Symbols for Nucleic Acids, Polynucleotides and Their Constituents" (PDF). International Union of Pure and Applied Chemistry. Retrieved 5 December 2020.
  14. ^ "What does DNA do?". Your Genome. Welcome Genome Campus. Archived from the original on 29 November 2020. Retrieved 12 January 2021.
  15. ^ "Genes". DNA, Genetics, and Evolution. Boston University. Archived from the original on 28 April 2020. Retrieved 10 December 2020.
  16. ^ a b c Osawa, A (November 1993). "Evolutionary changes in the genetic code". Comparative Biochemistry and Physiology. 106 (2): 489–94. doi:10.1016/0305-0491(93)90122-l. PMID 8281749.
  17. ^ a b c d Osawa S, Jukes TH, Watanabe K, Muto A (March 1992). "Recent evidence for evolution of the genetic code". Microbiological Reviews. 56 (1): 229–64. doi:10.1128/MR.56.1.229-264.1992. PMC 372862. PMID 1579111.

Further reading[edit]

External links[edit]