Enables DNA helicase activity. Involved in mitochondrial DNA replication. Acts upstream of or within DNA unwinding involved in DNA replication. Located in mitochondrion. Used to study Parkinson's disease. Human ortholog(s) of this gene implicated in Perrault syndrome; autosomal dominant progressive external ophthalmoplegia with mitochondrial DNA deletions 3; chronic progressive external ophthalmoplegia; and mitochondrial DNA depletion syndrome 7. Orthologous to human TWNK (twinkle mtDNA helicase). [provided by Alliance of Genome Resources, Apr 2022]