Human mitochondrial DNA polymerase has been implicated in drug toxicity of antiviral drugs designed against HIV reverse transcriptase.  We use structures of human mitochondrial DNA polymerase as a guide for designing more potent and less toxicity antiviral reagents. 

Gene expression system in mitochondria shows a clear viral origin:   The mitochondrial RNA polymerase active site domain resembles that of T7 bacteriophage.  However, mitoRNA polymerase differs from T7 RNA polymerase by functionally depending on transcription factors.  Studies of mitochondrial transcription not only provides us important links between human diseases and  gene expression defects, but also an valuable point on evolution of transcription systems.