Carboxyl-terminal domain III of the delta' subunit of the DNA polymerase III holoenzyme binds delta. Journal Article uri icon



  • The delta and delta' subunits are essential components of the DNA polymerase III holoenzyme, required for assembly and function of the DnaX-complex clamp loader (tau2gammadeltadelta'chipsi). The x-ray crystal structure of delta' contains three structural domains (Guenther, B., Onrust, R., Sali, A., O'Donnell, M., and Kuriyan, J. (1997) Cell 91, 335-345). In this study, we localize the delta-binding domain of delta' to a carboxyl-terminal domain III by quantifying the interaction of delta with a series of delta' fusion proteins lacking specific domains. Purification and immobilization of the fusion proteins were facilitated by the inclusion of a tag containing hexahistidine and a short biotinylation sequence. Both NH2- and COOH-terminal-tagged full-length delta' were soluble and had specific activities comparable with that of native delta'. delta and delta' form a 1:1 heterodimer with a dissociation constant (K(D)) of 5 x 10(-7) m determined by equilibrium sedimentation. The K(D) determined by surface plasmon resonance was comparable. Domain III alone bound delta at an affinity comparable to that of wild type delta', whereas proteins lacking domain III did not bind delta. Using a panel of domain-specific anti-delta' monoclonal antibodies, we found that two of the domain III-specific monoclonal antibodies interfered with delta-delta' interaction and abolished the replication activity of DNA polymerase-III holoenzyme.

publication date

  • November 2, 2001

has subject area

has restriction

  • hybrid

Date in CU Experts

  • October 1, 2013 12:09 PM

Full Author List

  • Song MS; Dallmann HG; McHenry CS

author count

  • 3

Other Profiles

International Standard Serial Number (ISSN)

  • 0021-9258

Additional Document Info

start page

  • 40668

end page

  • 40679


  • 276


  • 44