University of Wollongong
Browse

Strand separation establishes a sustained lock at the Tus-Ter replication fork barrier

Download (2.59 MB)
journal contribution
posted on 2024-11-16, 07:18 authored by Bojk A Berghuis, David Dulin, Zhi-Qiang XuZhi-Qiang Xu, Theo van Laar, Bronwen Cross, Richard Janissen, Slobodan Jergic, Nicholas DixonNicholas Dixon, Martin Depken, Nynke H Dekker
The bidirectional replication of a circular chromosome by many bacteria necessitates proper termination to avoid the head-on collision of the opposing replisomes. In Escherichia coli, replisome progression beyond the termination site is prevented by Tus proteins bound to asymmetric Ter sites. Structural evidence indicates that strand separation on the blocking (nonpermissive) side of Tus-Ter triggers roadblock formation, but biochemical evidence also suggests roles for protein-protein interactions. Here DNA unzipping experiments demonstrate that nonpermissively oriented Tus-Ter forms a tight lock in the absence of replicative proteins, whereas permissively oriented Tus-Ter allows nearly unhindered strand separation. Quantifying the lock strength reveals the existence of several intermediate lock states that are impacted by mutations in the lock domain but not by mutations in the DNA-binding domain. Lock formation is highly specific and exceeds reported in vivo efficiencies. We postulate that protein-protein interactions may actually hinder, rather than promote, proper lock formation.

Funding

Functional Dissection of the Bacterial Replisome

Australian Research Council

Find out more...

History

Citation

Berghuis, B. A., Dulin, D., Xu, Z., van Laar, T., Cross, B., Janissen, R., Jergic, S., Dixon, N. E., Depken, M. & Dekker, N. H. (2015). Strand separation establishes a sustained lock at the Tus-Ter replication fork barrier. Nature Chemical Biology, 11 (8), 579-585.

Journal title

Nature Chemical Biology

Volume

11

Issue

8

Pagination

579-585

Language

English

RIS ID

102266

Usage metrics

    Categories

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC