Mitochondrial genome maintenance exonuclease 1, abbreviated as MGME1, is an enzyme that in humans is encoded by the MGME1 gene. MGME1 is a 344 amino acids long protein belonging to the PD-(D/E)XK family of nucleases. It localizes to mitochondria where it is important for maintenance of the mitochondrial genome. Loss of function mutations in MGME1 lead to defects in mitochondrial DNA, including mitochondrial DNA depletion, duplications, deletions and increased replication intermediates. Also, there is an accumulation of 7S DNA, a short single stranded linear DNA strand. MGME1 deficiency in humans leads to multisystemic mitochondrial disease.
