The Tus-Ter protein-DNA complex of Escherichia coli blocks progression of DNA replication from only one direction at the replication terminus. As the replication fork helicase unwinds one side of Ter, a conserved cytosine flips out of the duplex and binds to Tus, thereby creating a locked complex that blocks the advancing helicase. © 2006 Elsevier Ltd. All rights reserved.
Kaplan, D. L. (2006, September 5). Replication Termination: Mechanism of Polar Arrest Revealed. Current Biology. https://doi.org/10.1016/j.cub.2006.08.013