mechanisms of mitochondrial DNA damage

Last reviewed 01/2018

Human mitochondrial DNA is a 16569 nucleotide double-stranded circular molecule which encodes proteins and structural RNAs such as tRNA.

Several features of the mitochondrial genome make it less stable:

  • the absence of introns hance a mutation is more likely to occur in a functionally significant area
  • the absence of protective histones
  • the absence of a DNA repair system
  • the high concentration of oxygen free radicals
  • mitochondrial DNA does not recombine and so mutations accumulate along a maternal inheritance

The mutation rate of mitochondrial DNA is 10 times greater than nuclear DNA.