A mitochondrial DNA polymerase from embryos of Drosophila melanogaster. Purification, subunit structure, and partial characterization

J Biol Chem. 1986 Nov 5;261(31):14764-70.

Abstract

The mitochondrial DNA polymerase has been purified to near-homogeneity from early embryos of Drosophila melanogaster. Sodium dodecyl sulfate gel electrophoresis of the highly purified enzyme reveals two polypeptides with molecular masses of 125,000 and 35,000 daltons, in a ratio of 1:1. The enzyme has a sedimentation coefficient of 7.6 S and a Stokes radius of 51 A. Taken together, the data suggest that the D. melanogaster DNA polymerase gamma is a heterodimer. DNA polymerase activity gel analysis has allowed the assignment of the DNA polymerization function to the large subunit. The DNA polymerase exhibits a remarkable ability to utilize efficiently a variety of template-primers including gapped DNA, poly(rA).oligo(dT) and singly primed phi X174 DNA. Both the crude and the highly purified enzymes are stimulated by KCl, and inhibited by dideoxythymidine triphosphate and by N-ethylmaleimide. Thus, the catalytic properties of the near-homogeneous Drosophila enzyme are consistent with those of DNA polymerase gamma as partially purified from several vertebrates.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • DNA-Directed DNA Polymerase / isolation & purification*
  • DNA-Directed DNA Polymerase / metabolism
  • Drosophila melanogaster / embryology
  • Drosophila melanogaster / enzymology*
  • Embryo, Nonmammalian / enzymology
  • Kinetics
  • Macromolecular Substances
  • Mitochondria / enzymology*
  • Molecular Weight
  • Protein Conformation
  • Substrate Specificity
  • Templates, Genetic

Substances

  • Macromolecular Substances
  • DNA-Directed DNA Polymerase