線粒體dna聚合酶是異三聚體，由一個副亞單位的同二聚體和一個催化亞單位組成。該基因編碼的蛋白質是線粒體dna聚合酶的催化亞單位。編碼的蛋白質在其n-末端附近含有一個可能是多態性的聚谷氨酸束。該基因的缺陷是漸進性外眼肌麻痹的原因，線粒體DNA缺失1（PUA1），感覺性共濟失調神經病變構音障礙和眼肌麻痹（SANDO），Alper-HuttutoLokes綜合征（AHS），和線粒體神經胃腸性腦病綜合征（MNGEE）。在這個基因中發現了兩個編碼相同蛋白質的轉錄變體。
Mitochondrial DNA polymerase is heterotrimeric, consisting of a homodimer of accessory subunits plus a catalytic subunit. The protein encoded by this gene is the catalytic subunit of mitochondrial DNA polymerase. The encoded protein contains a polyglutamine tract near its N-terminus that may be polymorphic. Defects in this gene are a cause of progressive external ophthalmoplegia with mitochondrial DNA deletions 1 (PEOA1), sensory ataxic neuropathy dysarthria and ophthalmoparesis (SANDO), Alpers-Huttenlocher syndrome (AHS), and mitochondrial neurogastrointestinal encephalopathy syndrome (MNGIE). Two transcript variants encoding the same protein have been found for this gene.