DNA polymerase-primase from embryos of Drosophila melanogaster. The DNA polymerase subunit

J Biol Chem. 1987 Nov 25;262(33):16100-4.


The DNA polymerase-primase from Drosophila melanogaster has been separated into its constituent polymerase and primase subunits by sedimentation in glycerol gradients containing 50% ethylene glycol. Both activities have been obtained in good yield. The properties of the 182-kDa polymerase subunit are similar to those of the intact four-subunit enzyme. However, there are three significant differences. (i) The polymerase activity of the 182-kDa subunit shows an increased thermolability; (ii) the pause sites during replication of singly primed, single-stranded circular DNA by the 182-kDa subunit are altered; and (iii) unlike the intact enzyme, the 182-kDa subunit is highly processive in the presence of the single-stranded DNA-binding protein of Escherichia coli.

Publication types

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

MeSH terms

  • Animals
  • DNA Primase
  • DNA-Directed DNA Polymerase / isolation & purification*
  • DNA-Directed DNA Polymerase / metabolism
  • Drosophila melanogaster / embryology
  • Drosophila melanogaster / enzymology*
  • Embryo, Nonmammalian / enzymology
  • Kinetics
  • Macromolecular Substances
  • Molecular Weight
  • RNA Nucleotidyltransferases / isolation & purification*
  • RNA Nucleotidyltransferases / metabolism


  • Macromolecular Substances
  • DNA Primase
  • RNA Nucleotidyltransferases
  • DNA-Directed DNA Polymerase