Are there special enzymes that unwind/transcribe mitochondrial DNA, as compared to enzymes that help transcribe cellular DNA?
Belen Hurle, Ph.D.: The mitochondrion is the energy producing organelle in the cell, and the only organelle in animal cells besides the nucleus that contains its own chromosome. Maintenance of mitochondrial function requires the replication and expression of the mitochondrial genome. Remarkably, not a single gene involved in mitochondrial molecular biology is encoded in the compact mitochondrial genome: all of the protein machinery for replication, transcription, and translation (and DNA repair functions) is encoded in the nucleus, and the relevant proteins must be imported into the mitochondrion.
