Structure of the RTP-DNA complex and the mechanism of polar replication fork arrestWilce, J.A., Vivian, J.P., Hastings, A.F., Otting, G., Folmer, R.H., Duggin, I.G., Wake, R.G., Wilce, M.C.
(2001) Nat Struct Biol 8: 206-210
- PubMed: 11224562
- DOI: https://doi.org/10.1038/84934
- Primary Citation of Related Structures:
- PubMed Abstract:
The coordinated termination of DNA replication is an important step in the life cycle of bacteria with circular chromosomes, but has only been defined at a molecular level in two systems to date. Here we report the structure of an engineered replication terminator protein (RTP) of Bacillus subtilis in complex with a 21 base pair DNA by X-ray crystallography at 2.5 A resolution. We also use NMR spectroscopic titration techniques. This work reveals a novel DNA interaction involving a dimeric 'winged helix' domain protein that differs from predictions. While the two recognition helices of RTP are in close contact with the B-form DNA major grooves, the 'wings' and N-termini of RTP do not form intimate contacts with the DNA. This structure provides insight into the molecular basis of polar replication fork arrest based on a model of cooperative binding and differential binding affinities of RTP to the two adjacent binding sites in the complete terminator.
Department of Chemistry/Biochemistry University of Western Australia and the Western Australian Institute for Medical Research, Nedlands, Western Australia 6907 Australia.