- The eukaryotic single-subunit mitochondrial RNA polymerase was ganked from bacterial viruses (bacteriophage T3/T7), and has no relation to those encoded by bacteria themselves.
- Even weirder, the phage-like mtRNA polymerase is encoded in the nuclear genome of eukaryotes. Interstingly, an isoform of mtRNA polymerase lacking a mitochondrial localization signal performs transcription of nuclear-encoded genes in the nucleus (RNA pol IV).
- The amino-terminal domain of yeast mtRNA polymerase has diverged from its phage ancestry, and has evolved to mediate coupling between mitochondrial transcription and translation. In fact, mutations in the ATD lead to deficiencies in mitochondrially-encoded OXPHOS enzymes and thereby decrease lifespan in yeast.
- What? Mitochondrial translation? What's up with that? Nobody really knows...
Also, check out this wicked album of artistic renditions of cells by Gary Carlson which I ganked the above photo from. Nice job Gary!