Each monomer of the dimeric accessory protein for human mitochondrial DNA polymerase has a distinct role in conferring processivity

Young Sam Lee, Sujin Lee, Borries Demeler, Ian J. Molineux, Kenneth A. Johnson, Y. Whitney Yin

Research output: Contribution to journalArticle

33 Scopus citations


The accessory protein polymerase (pol) γB of the human mitochondrial DNA polymerase stimulates the synthetic activity of the catalytic subunit. pol γB functions by both accelerating the polymerization rate and enhancing polymerase-DNA interaction, thereby distinguishing itself from the accessory subunits of other DNA polymerases. The molecular basis for the unique functions of human pol γB lies in its dimeric structure, where the pol γB monomer proximal to pol γA in the holoenzyme strengthens the interaction with DNA, and the distal pol γB monomer accelerates the reaction rate. We further show that human pol γB exhibits a catalytic subunit- and substrate DNA-dependent dimerization. By duplicating the monomeric pol γB of lower eukaryotes, the dimeric mammalian proteins confer additional processivity to the holoenzyme polymerase.

Original languageEnglish (US)
Pages (from-to)1490-1499
Number of pages10
JournalJournal of Biological Chemistry
Issue number2
StatePublished - Jan 19 2010
Externally publishedYes


ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

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