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
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
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.