The vertebrate mitochondrial code (translation table 2) is the genetic code found in the mitochondria of all vertebrata.
Evolution AGA and AGG were thought to have become mitochondrial stop codons early in vertebrate evolution. However, at least in humans it has now been shown that AGA and AGG sequences are not recognized as termination codons. A -1 mitoribosome frameshift occurs at the AGA and AGG codons predicted to terminate the CO1 and ND6 open reading frames (ORFs), and consequently both ORFs terminate in the standard UAG codon.
Incomplete stop codons Mitochondrial genes in some vertebrates (including humans) have incomplete stop codons ending in U or UA, which become complete termination codons (UAA) upon subsequent polyadenylation.
Translation table
Amino acids biochemical properties nonpolar polar basic acidic Termination: stop codon
+ Mitochondrial genetic code 1stbase 2nd base 3rdbase U C A G U UUU (Phe/F) Phenylalanine UCU (Ser/S) Serine UAU (Tyr/Y) Tyrosine UGU (Cys/C) Cysteine U UUC UCC UAC UGC C UUA (Leu/L) Leucine UCA UAA Stop UGA (Trp/W) Tryptophan A UUG UCG UAG UGG G C CUU CCU (Pro/P) Proline CAU (His/H) HistidineCGU (Arg/R) Arginine UCUCCCCCACCGC CCUACCACAA (Gln/Q) GlutamineCGA ACUGCCGCAGCGG G AAUU (Ile/I) IsoleucineACU (Thr/T) Threonine AAU (Asn/N) AsparagineAGU (Ser/S) Serine UAUCACCAACAGC CAUA (Met/M) MethionineACAAAA (Lys/K) LysineAGA Stop AAUG ACGAAGAGG G GGUU (Val/V) ValineGCU (Ala/A) AlanineGAU (Asp/D) Aspartic acidGGU (Gly/G) Glycine UGUCGCCGACGGC CGUAGCAGAA (Glu/E) Glutamic acidGGA AGUGGCGGAGGGG G The codon AUG both codes for methionine and serves as an initiation site: the first AUG in an mRNA's coding region is where translation into protein begins.
Differences from the standard code
+ DNA codons RNA codons This code (2) Standard code (1) AGA AGA STOP = Ter (*) Arg (R) AGG AGG STOP = Ter (*) Arg (R) ATA AUA Met (M) Ile (I) TGA UGA Trp (W) STOP = Ter (*)
Alternative initiation codons Bos: AUA Homo: AUA, AUU Mus: AUA, AUU, AUC Coturnix, Gallus: also GUG
See also List of genetic codes
References This article contains public domain text from the NCBI page compiled by Andrzej Elzanowski and Jim Ostell.The Genetic Codes