Solution structure of the helicase-interaction domain of the primase DnaG: a model for helicase activation
Syson, K., Thirlway, J., Hounslow, A.M., Soultanas, P., Waltho, J.P.(2005) Structure 13: 609-616
- PubMed: 15837199
- DOI: https://doi.org/10.1016/j.str.2005.01.022
- Primary Citation of Related Structures:
1Z8S - PubMed Abstract:
The helicase-primase interaction is a critical event in DNA replication and is mediated by a putative helicase-interaction domain within the primase. The solution structure of the helicase-interaction domain of DnaG reveals that it is made up of two independent subdomains: an N-terminal six-helix module and a C-terminal two-helix module that contains the residues of the primase previously identified as important in the interaction with the helicase. We show that the two-helix module alone is sufficient for strong binding between the primase and the helicase but fails to activate the helicase; both subdomains are required for helicase activation. The six-helix module of the primase has only one close structural homolog, the N-terminal domain of the corresponding helicase. This surprising structural relationship, coupled with the differences in surface properties of the two molecules, suggests how the helicase-interaction domain may perturb the structure of the helicase and lead to activation.
Organizational Affiliation:
Department of Molecular Biology and Biotechnology, Krebs Institute, Western Bank, University of Sheffield, Sheffield S10 2TN, United Kingdom.