Print Email Facebook Twitter Strand separation establishes a sustained lock at the Tus-Ter replication fork barrier Title Strand separation establishes a sustained lock at the Tus-Ter replication fork barrier Author Berghuis, B.A. (TU Delft BN/Nynke Dekker Lab; Kavli institute of nanoscience Delft) Dulin, D. (TU Delft BN/Nynke Dekker Lab; Kavli institute of nanoscience Delft) Xu, Zhi Qiang (University of Wollongong) van Laar, T. (TU Delft BN/Nynke Dekker Lab; Kavli institute of nanoscience Delft) Cross, B. (TU Delft BN/Cees Dekker Lab; Karlstad University; Kavli institute of nanoscience Delft) Janissen, R. (TU Delft BN/Nynke Dekker Lab; Kavli institute of nanoscience Delft) Jergic, Slobodan (University of Wollongong) Dixon, Nicholas E. (University of Wollongong) Depken, S.M. (TU Delft BN/Martin Depken Lab; Kavli institute of nanoscience Delft) Dekker, N.H. (TU Delft BN/Nynke Dekker Lab; Kavli institute of nanoscience Delft) Date 2015 Abstract 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. Subject DNA-binding proteinsnucleic acidssingle-molecule biophysics To reference this document use: http://resolver.tudelft.nl/uuid:376b7dc9-92d7-4ee7-9abf-daa1c33613f4 DOI https://doi.org/10.1038/nchembio.1857 ISSN 1552-4450 Source Nature Chemical Biology, 11, 579-585 Bibliographical note Accepted Author Manuscript Part of collection Institutional Repository Document type journal article Rights © 2015 B.A. Berghuis, D. Dulin, Zhi Qiang Xu, T. van Laar, B. Cross, R. Janissen, Slobodan Jergic, Nicholas E. Dixon, S.M. Depken, N.H. Dekker Files PDF print_artikel_20150413_Tu ... inal_A.pdf 752.02 KB Close viewer /islandora/object/uuid:376b7dc9-92d7-4ee7-9abf-daa1c33613f4/datastream/OBJ/view