DNA polymerase subunit gamma-2, mitochondrial (POLG2)

DNA polymerase subunit gamma-2, mitochondrial (POLG2) is the 55 kDa accessory subunit of the mitochondrial DNA polymerase gamma complex. The holoenzyme comprises one catalytic subunit (POLG) and a dimer of POLG2, forming a heterotrimeric structure. POLG2 enhances the affinity of the POLG catalytic subunit for DNA, increases processivity (enabling long-chain DNA synthesis), and confers salt tolerance to the complex. It fulfills essential functions in mitochondrial DNA replication and maintenance; mutations in POLG2 therefore result in depletion and deletions of mitochondrial genomes, presenting as progressive external ophthalmoplegia and other systemic manifestations. POLG2 directly binds DNA, can oligomerize, and is thought to play structure-specific roles in targeting forked or crossed DNA structures in the mitochondrial nucleoid. Genetic disruption leads to mitochondrial dysfunction and multisystemic disease; no direct drugs presently target POLG2 but its role is central to mitochondrial genetic stability.

Other names

POLG2HP55MTPOLBPEOA4POLBPOLG-BETAPOLGBpolymerase (DNA) gamma 2, accessory subunitDNA polymerase gamma 2, accessory subunitMTDPS16MTDPS16AMTDPS16BDNA polymerase gamma accessory 55 kDa subunitMitochondrial DNA polymerase accessory subunitp55Polymerase (DNA directed), gamma 2, accessory subunit

No drugs with a characterized mechanism targeting POLG2; inhibition would reduce mitochondrial DNA replication