Bacteriophage origins of mitochondrial replication and transcription proteins

Trends Genet. 2006 Feb;22(2):90-5. doi: 10.1016/j.tig.2005.11.007. Epub 2005 Dec 20.


Mounting evidence suggests that key components of the mitochondrial transcription and replication apparatus are derived from the T-odd lineage of bacteriophage rather than from an alpha-Proteobacterium, as the endosymbiont hypothesis would predict. We propose that several mitochondrial replication genes were acquired together from an ancestor of T-odd phage early in the evolution of the eukaryotic cell, at the time of the mitochondrial endosymbiosis. We further propose that at a later stage the single-subunit RNA polymerase, originally acquired for mitochondrial DNA replication, was co-opted to serve in mitochondrial transcription.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Bacteriophage T7 / genetics*
  • DNA Replication
  • DNA, Mitochondrial / genetics*
  • DNA-Directed RNA Polymerases
  • Mitochondria / metabolism*
  • Replication Origin
  • Transcription, Genetic*


  • DNA, Mitochondrial
  • DNA-Directed RNA Polymerases