DNA and RNA codon tables
Appearance
The genetic code is traditionally represented as an RNA codon table because, when proteins are made in a cell by ribosomes, it is mRNA that directs protein synthesis. The mRNA sequence is determined by the sequence of genomic DNA. With the rise of computational biology and genomics, most genes are now discovered at the DNA level, so a DNA codon table is becoming increasingly useful.[1] The DNA codons in such tables occur on the sense DNA strand and are arranged in a 5' → 3' direction.
Amino-acid biochemical properties | Nonpolar | Polar | Basic | Acidic | Termination: stop codon |
1st base |
2nd base | 3rd base | |||||||
---|---|---|---|---|---|---|---|---|---|
T | C | A | G | ||||||
T | TTT | (Phe/F) Phenylalanine | TCT | (Ser/S) Serine | TAT | (Tyr/Y) Tyrosine | TGT | (Cys/C) Cysteine | T |
TTC | TCC | TAC | TGC | C | |||||
TTA | (Leu/L) Leucine | TCA | TAA | Stop (Ochre)[B] | TGA | Stop (Opal)[B] | A | ||
TTG[A] | TCG | TAG | Stop (Amber)[B] | TGG | (Trp/W) Tryptophan | G | |||
C | CTT | CCT | (Pro/P) Proline | CAT | (His/H) Histidine | CGT | (Arg/R) Arginine | T | |
CTC | CCC | CAC | CGC | C | |||||
CTA | CCA | CAA | (Gln/Q) Glutamine | CGA | A | ||||
CTG | CCG | CAG | CGG | G | |||||
A | ATT | (Ile/I) Isoleucine | ACT | (Thr/T) Threonine | AAT | (Asn/N) Asparagine | AGT | (Ser/S) Serine | T |
ATC | ACC | AAC | AGC | C | |||||
ATA | ACA | AAA | (Lys/K) Lysine | AGA | (Arg/R) Arginine | A | |||
ATG[A] | (Met/M) Methionine | ACG | AAG | AGG | G | ||||
G | GTT | (Val/V) Valine | GCT | (Ala/A) Alanine | GAT | (Asp/D) Aspartic acid | GGT | (Gly/G) Glycine | T |
GTC | GCC | GAC | GGC | C | |||||
GTA | GCA | GAA | (Glu/E) Glutamic acid | GGA | A | ||||
GTG[A] | GCG | GAG | GGG | G |
- A Possible start codons in NCBI table 1. ATG is most common.[3] The two other start codons listed by table 1 (GTG and TTG) are rare in eukaryotes.[4] Prokaryotes have less strigent start codon requirements; they are described by NCBI table 11.
- B ^ ^ ^ The historical basis for designating the stop codons as amber, ochre and opal is described in an autobiography by Sydney Brenner[5] and in a historical article by Bob Edgar.[6]
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, CTG, UTG | HTG | STOP | TAA, TGA, TAG | TRA, TAR |
See also
References
- ^ Kimball, John (2014-05-01). "The Genetic Code". Kimball's Biology Pages.
- ^ Elzanowski A, Ostell J (7 January 2019). "The Genetic Codes". National Center for Biotechnology Information. Archived from the original on 5 October 2020. Retrieved 21 February 2019.
- ^ Nakamoto T (March 2009). "Evolution and the universality of the mechanism of initiation of protein synthesis". Gene. 432 (1–2): 1–6. doi:10.1016/j.gene.2008.11.001. PMID 19056476.
- ^ Asano, K (2014). "Why is start codon selection so precise in eukaryotes?". Translation (Austin, Tex.). 2 (1): e28387. doi:10.4161/trla.28387. PMID 26779403.
- ^ Brenner S. A Life in Science (2001) Published by Biomed Central Limited ISBN 0-9540278-0-9 see pages 101-104
- ^ Edgar B (2004). "The genome of bacteriophage T4: an archeological dig". Genetics. 168 (2): 575–82. PMC 1448817. PMID 15514035. see pages 580-581