DNA codon table

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.

nonpolar

polar

basic

acidic

(stop codon)

Standard genetic code

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)	TGA	Stop (Opal)	A
	TTG		TCG		TAG	Stop (Amber)	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		GCG		GAG		GGG		G

^A The codon ATG both codes for methionine and serves as an initiation site: the first ATG in an mRNA's coding region is where translation into protein begins.^[2]

Inverse table (compressed using IUPAC notation)

Amino acid	Codons	Compressed		Amino acid	Codons	Compressed
Ala/A	GCT, GCC, GCA, GCG	GCN		Leu/L	TTA, TTG, CTT, CTC, CTA, CTG	YTR, CTN
Arg/R	CGT, CGC, CGA, CGG, AGA, AGG	CGN, MGR		Lys/K	AAA, AAG	AAR
Asn/N	AAT, AAC	AAY		Met/M	ATG
Asp/D	GAT, GAC	GAY		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
Gly/G	GGT, GGC, GGA, GGG	GGN		Trp/W	TGG
His/H	CAT, CAC	CAY		Tyr/Y	TAT, TAC	TAY
Ile/I	ATT, ATC, ATA	ATH		Val/V	GTT, GTC, GTA, GTG	GTN
START	ATG			STOP	TAA, TGA, TAG	TAR, TRA

See also

• RNA codon table
• RNA
• List of genetic codes

References

1. Kimball, John (2014-05-01). "The Genetic Code". Kimball's Biology Pages.
2. 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.