What is all this fuss about Tus?

What is all this fuss about Tus?: Comparison of recent findings from biophysical and biochemical experiments

Berghuis, B.A. (TU Delft BN/Nynke Dekker Lab)
Raducanu, Vlad-Stefan (King Abdullah University of Science and Technology)
Elshenawy, Mohamed M. (King Abdullah University of Science and Technology)
Jergic, Slobodan (University of Wollongong)
Depken, S.M. (TU Delft BN/Martin Depken Lab)
Dixon, NE (University of Wollongong)
Hamdan, Samir M. (King Abdullah University of Science and Technology)
Dekker, N.H. (TU Delft BN/Nynke Dekker Lab)

2017-11-06

Synchronizing the convergence of the two-oppositely moving DNA replication machineries at specific termination sites is a tightly coordinated process in bacteria. In Escherichia coli, a “replication fork trap” – found within a chromosomal region where forks are allowed to enter but not leave – is set by the protein–DNA roadblock Tus–Ter. The exact sequence of events by which Tus–Ter blocks replisomes approaching from one direction but not the other has been the subject of controversy for many decades. Specific protein–protein interactions between the nonpermissive face of Tus and the approaching helicase were challenged by biochemical and structural studies. These studies show that it is the helicase-induced strand separation that triggers the formation of new Tus–Ter interactions at the nonpermissive face – interactions that result in a highly stable “locked” complex. This controversy recently gained renewed attention as three single-molecule-based studies scrutinized this elusive Tus–Ter mechanism – leading to new findings and refinement of existing models, but also generating new questions. Here, we discuss and compare the findings of each of the single-molecule studies to find their common ground, pinpoint the crucial differences that remain, and push the understanding of this bipartite DNA–protein system further.

DNA–protein interactions
DNA replication
prokaryotic replication
replication termination
replisome
Tus–Ter
single-molecule techniques
magnetic tweezers

http://resolver.tudelft.nl/uuid:5940a265-aeb4-46d3-a90b-3e05a25d1279

https://doi.org/10.1080/10409238.2017.1394264

1040-9238

Critical Reviews in Biochemistry and Molecular Biology, 1-15

Institutional Repository

journal article

© 2017 B.A. Berghuis, Vlad-Stefan Raducanu, Mohamed M. Elshenawy, Slobodan Jergic, S.M. Depken, NE Dixon, Samir M. Hamdan, N.H. Dekker