A different genetic code in human mitochondria

Nature. 1979 Nov 8;282(5735):189-94. doi: 10.1038/282189a0.


Comparison of the human mitochrondial DNA sequence of the cytochrome oxidase subunit II gene and the sequence of the corresponding beef heart protein shows that UGA is used as a tryptophan codon and not as a termination codon and suggests that AUA may be a methionine and not an isoleucine codon. The cytochrome oxidase II gene is contiguous at its 5' end with a tRNAAsp gene and there are only 25 bases at its 3' end before a tRNALys gene. These tRNA'S are different from all other known tRNA sequences.

MeSH terms

  • Aspartic Acid / genetics
  • Base Sequence
  • Codon
  • DNA, Mitochondrial / genetics*
  • Electron Transport Complex IV / genetics*
  • Genes
  • Genetic Code*
  • Humans
  • Isoleucine / genetics
  • Lysine / genetics
  • Methionine / genetics
  • RNA, Transfer / genetics
  • Tryptophan / genetics


  • Codon
  • DNA, Mitochondrial
  • Isoleucine
  • Aspartic Acid
  • Tryptophan
  • RNA, Transfer
  • Methionine
  • Electron Transport Complex IV
  • Lysine