An Interaction between DNA Polymerase and Helicase Is Essential for the High Processivity of the Bacteriophage T7 Replisome |
| |
| Authors: | Arkadiusz W. Kulczyk Barak Akabayov Seung-Joo Lee Mihnea Bostina Steven A. Berkowitz Charles C. Richardson |
| |
| Affiliation: | From the ‡Department of Biological Chemistry and Molecular Pharmacology, Harvard University Medical School, Boston, Massachusetts 02115.;the §Facility for Electron Microscopy Research, McGill University, Montreal, Quebec H3A 2B2, Canada, and ;¶Biogen Idec, Inc., Cambridge, Massachusetts 02142 |
| |
| Abstract: | Synthesis of the leading DNA strand requires the coordinated activity of DNA polymerase and DNA helicase, whereas synthesis of the lagging strand involves interactions of these proteins with DNA primase. We present the first structural model of a bacteriophage T7 DNA helicase-DNA polymerase complex using a combination of small angle x-ray scattering, single-molecule, and biochemical methods. We propose that the protein-protein interface stabilizing the leading strand synthesis involves two distinct interactions: a stable binding of the helicase to the palm domain of the polymerase and an electrostatic binding of the carboxyl-terminal tail of the helicase to a basic patch on the polymerase. DNA primase facilitates binding of DNA helicase to ssDNA and contributes to formation of the DNA helicase-DNA polymerase complex by stabilizing DNA helicase. |
| |
| Keywords: | DNA Helicase DNA Polymerase DNA Primase DNA Replication Electron Microscopy (EM) Single-molecule Biophysics X-ray Scattering |
|
|
