Invertebrate mitochondrial code

 The invertebrate mitochondrial code (translation table 5) is a genetic code used by the mitochondrial genome of invertebrates.

The codeEdit

   AAs = FFLLSSSSYY**CCWWLLLLPPPPHHQQRRRRIIMMTTTTNNKKSSSSVVVVAAAADDEEGGGG
Starts = ---M----------------------------MMMM---------------M------------
 Base1 = TTTTTTTTTTTTTTTTCCCCCCCCCCCCCCCCAAAAAAAAAAAAAAAAGGGGGGGGGGGGGGGG
 Base2 = TTTTCCCCAAAAGGGGTTTTCCCCAAAAGGGGTTTTCCCCAAAAGGGGTTTTCCCCAAAAGGGG
 Base3 = TCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAG

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 codeEdit

DNA codonsRNA codonsThis code (5)Standard code (1)
AGAAGASer (S)Arg (R)
AGGAGGSer (S)Arg (R)
ATAAUAMet (M)Ile (I)
TGAUGATrp (W)STOP = Ter (*)

Note: The codon AGG is absent in Drosophila.[1]

Alternative initiation codonsEdit

  • AUA, AUU
  • AUC: Apis [2]
  • GUG: Polyplacophora[3]
  • UUG: Ascaris, Caenorhabditis.

Systematic rangeEdit

  • Nematoda: Ascaris, Caenorhabditis ;
  • Mollusca: Bivalvia);[4] Polyplacophora;[3]
  • Arthropoda/Crustacea: Artemia;[5]
  • Arthropoda/Insecta: Drosophila [Locusta migratoria (migratory locust), Apis mellifera (honeybee)].

Other variationsEdit

  • Several arthropods translate the codon AGG as lysine instead of serine (as in the Pterobranchia Mitochondrial Code) or arginine (as in the standard genetic code).[6]
  • GUG may possibly function as an initiator in Drosophila.[7][8] AUU is not used as an initiator in Mytilus[4]
  • "An exceptional mechanism must operate for initiation of translation of the cytochrome oxidase subunit I mRNA in both D. melanogaster[9] and D. yakuba,[10] since its only plausible initiation codon, AUA, is out of frame with the rest of the gene. Initiation appears to require the "reading" of an AUAA quadruplet, which would be equivalent to initiation at AUA followed immediately by a specific ribosomal frameshift. Another possible mechanism ... is that the mRNA is "edited" to bring the AUA initiation into frame." [11]

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 Metasyntactic variable, which is released under the 
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