tau binds and organizes Escherichia coli replication proteins through distinct domains. Domain IV, located within the unique C terminus of tau, binds the replication fork, helicase, DnaB. Journal Article uri icon



  • Interaction between the tau subunit of the DNA polymerase III holoenzyme and the DnaB helicase is critical for coupling the replicase and the primosomal apparatus at the replication fork (Kim, S., Dallmann, H. G., McHenry, C. S., and Marians, K. J. (1996) Cell 84, 643-650). In the preceding manuscript, we reported the identification of five putative structural domains within the tau subunit (Gao, D., and McHenry, C. (2000) J. Biol. Chem. 275, 4433-4440). As part of our systematic effort to assign functions to each of these domains, we expressed a series of truncated, biotin-tagged tau fusion proteins and determined their ability to bind DnaB by surface plasmon resonance on streptavidin-coated surfaces. Only tau fusion proteins containing domain IV bound DnaB. The DnaB-binding region was further limited to a highly basic 66-amino acid residue stretch within domain IV. Unlike the binding of immobilized tau(4) to the DnaB hexamer, the binding of monomeric domain IV to DnaB(6) was dependent upon the density of immobilized domain IV, indicating that DnaB(6) is bound by more than one tau protomer. This observation implies that both the leading and lagging strand polymerases are tethered to the DnaB helicase via dimeric tau. These double tethers of the leading and lagging strand polymerases proceeding through the tau-tau link and an additional tau-DnaB link are likely important for the dynamic activities of the replication fork.

publication date

  • February 9, 2001

has subject area

has restriction

  • hybrid

Date in CU Experts

  • October 1, 2013 12:09 PM

Full Author List

  • Gao D; McHenry CS

author count

  • 2

Other Profiles

International Standard Serial Number (ISSN)

  • 0021-9258

Additional Document Info

start page

  • 4441

end page

  • 4446


  • 276


  • 6