τ Binds and Organizes Escherichia coli Replication Proteins through Distinct Domains

D. Gao,C. McHenry

Published 2001 in Journal of Biological Chemistry

ABSTRACT

The τ subunit dimerizes Escherichia coli DNA polymerase III core through interactions with the α subunit. In addition to playing critical roles in the structural organization of the holoenzyme, τ mediates intersubunit communications required for efficient replication fork function. We identified potential structural domains of this multifunctional subunit by limited proteolysis of C-terminal biotin-tagged τ proteins. The cleavage sites of each of eight different proteases were found to be clustered within four regions of the τ subunit. The second susceptible region corresponds to the hinge between domain II and III of the highly homologous δ′ subunit, and the third region is near the C-terminal end of the τ-δ′ alignment (Guenther, B., Onrust, R., Sali, A., O'Donnell, M., and Kuriyan, J. (1997) Cell 91, 335–345). We propose a five-domain structure for the τ protein. Domains I and II are based on the crystallographic structure of δ′ by Guenther and colleagues. Domains III–V are based on our protease cleavage results. Using this information, we expressed biotin-tagged τ proteins lacking specific protease-resistant domains and analyzed their binding to the α subunit by surface plasmon resonance. Results from these studies indicated that the α binding site of τ lies within its C-terminal 147 residues (domain V).

PUBLICATION RECORD

CITATION MAP

EXTRACTION MAP

CLAIMS

  • No claims are published for this paper.

CONCEPTS

  • No concepts are published for this paper.

REFERENCES

Showing 1-27 of 27 references · Page 1 of 1

CITED BY

Showing 1-85 of 85 citing papers · Page 1 of 1