mitochondrial genome

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Genetics

the genetic code of mitochondria differs from the genetic code of nuclear or prokaryotic DNA
the codon UGA codes for Trp, rather than for termination, AUA codes for methionine rather than isoleucine, & AGA & AGG specify stop codons rather than Arg
the H strand (denser of 2 strands) encodes all of the RNA & protein products except for 1 protein & 14 tRNA's encoded by the L strand
a single primary transcript arises from the H strand, & another from the L strand
these transcripts are cleaved on either side of tRNA sequences
the mitochondrial genome is extensively polymorphic
mitochondrial mutation rates are 10X that of nuclear DNA & there is little to no DNA repair

↑ Brown et al FASEB J 6:2791 1992
↑ Textbook of Biochemistry with Clinical Correlations, 3rd ed., TM Devlin (ed), Wiley-Liss, NY 1992 pg 839
↑ Marzuki et al Hum Genet 88:139 1991
↑ Stryer Biochemistry WH Freeman & Co, New York, 1988 pg 833