Purification and characterization of DNA polymerase III'. Identification of tau as a subunit of the DNA polymerase III holoenzyme. Journal Article uri icon



  • DNA polymerase III', a new form of DNA polymerase III, has been purified 15,000-fold to 90% homogeneity from an Escherichia coli K12 strain. DNA polymerase III's is a subassembly of four subunits of the DNA polymerase III holoenzyme; it has functional and physical properties intermediate between the core DNA polymerase III and holoenzyme. Polyacrylamide gel electrophoresis performed under denaturing conditions indicates DNA polymerase III' to be a complex of the alpha, epsilon, and theta subunits of DNA polymerase III and a newly assigned subunit of the DNA polymerase III holoenzyme, tau (Mr = 83,000). Both gel filtration and phosphocellulose chromatography separate DNA polymerase III from DNA polymerase III'. All enzyme forms can utilize a duplex template containing short gaps. DNA polymerase III', like the DNA polymerase III holoenzyme, can synthesize DNA on a long single-stranded template in the presence of 5 mM spermidine; DNA polymerase III cannot. Alone, DNA polymerase III' is inert in the G4 natural replicative system in which the DNA polymerase III holoenzyme is active. Molecular weight and subunit stoichiometry determinations suggest that DNA polymerase III' contains two units of core DNA polymerase III and two tau subunits.

publication date

  • March 10, 1982

Date in CU Experts

  • October 1, 2013 12:09 PM

Full Author List

  • McHenry CS

author count

  • 1

Other Profiles

International Standard Serial Number (ISSN)

  • 0021-9258

Additional Document Info

start page

  • 2657

end page

  • 2663


  • 257


  • 5