Download MendeleyNMR structure of the N-terminal domain of E. coli DnaB helicase: implications for structure rearrangements in the helicase hexamer.
Weigelt, J., Brown, S.E., Miles, C.S., Dixon, N.E., Otting, G.(1999) Structure 7: 681-690
- PubMed: 10404597
- DOI: https://doi.org/10.1016/s0969-2126(99)80089-6
- Primary Citation of Related Structures:
1JWE - PubMed Abstract:
DnaB is the primary replicative helicase in Escherichia coli. Native DnaB is a hexamer of identical subunits, each consisting of a larger C-terminal domain and a smaller N-terminal domain. Electron-microscopy data show hexamers with C6 or C3 symmetry, indicating large domain movements and reversible pairwise association. The three-dimensional structure of the N-terminal domain of E. coli DnaB was determined by nuclear magnetic resonance (NMR) spectroscopy. Structural similarity was found with the primary dimerisation domain of a topoisomerase, the gyrase A subunit from E. coli. A monomer-dimer equilibrium was observed for the isolated N-terminal domain of DnaB. A dimer model with C2 symmetry was derived from intermolecular nuclear Overhauser effects, which is consistent with all available NMR data. The monomer-dimer equilibrium observed for the N-terminal domain of DnaB is likely to be of functional significance for helicase activity, by participating in the switch between C6 and C3 symmetry of the helicase hexamer.
Organizational Affiliation:
Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
