Ascidian mitochondrial code

The ascidian mitochondrial code (translation table 13) is a genetic code found in the mitochondria of Ascidia.

Code

<code>   AAs = FFLLSSSSYY**CCWWLLLLPPPPHHQQRRRRIIMMTTTTNNKKSSGGVVVVAAAADDEEGGGG</code>

<code>Starts = ---M------------------------------MM---------------M------------</code>

<code> Base1 = TTTTTTTTTTTTTTTTCCCCCCCCCCCCCCCCAAAAAAAAAAAAAAAAGGGGGGGGGGGGGGGG</code>

<code> Base2 = TTTTCCCCAAAAGGGGTTTTCCCCAAAAGGGGTTTTCCCCAAAAGGGGTTTTCCCCAAAAGGGG</code>

<code> Base3 = TCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAG</code>

Bases: adenine (A), cytosine (C), guanine (G) and thymine (T) or uracil (U).

Amino acids: Alanine (Ala, A), Arginine (Arg, R), Asparagine (Asn, N), Aspartic acid (Asp, D), Cysteine (Cys, C), Glutamic acid (Glu, E), Glutamine (Gln, Q), Glycine (Gly, G), Histidine (His, H), Isoleucine (Ile, I), Leucine (Leu, L), Lysine (Lys, K), Methionine (Met, M), Phenylalanine (Phe, F), Proline (Pro, P), Serine (Ser, S), Threonine (Thr, T), Tryptophan (Trp, W), Tyrosine (Tyr, Y), Valine (Val, V)

Differences from the standard code

Systematic range and comments

There is evidence from a phylogenetically diverse sample of tunicates (Urochordata) that AGA and AGG code for glycine. In other organisms, AGA/AGG code for either arginine or serine and in vertebrate mitochondria they code a STOP. Evidence for glycine translation of AGA/AGG was first found in 1993 in Pyura stolonifera and Halocynthia roretzi. It was then confirmed by tRNA sequencing and sequencing whole mitochondrial genomes.

Alternative initiation codons

ATA, GTG and TTG
ATT is the start codon for the CytB gene in Halocynthia roretzi.

References