Structural characterisation of the complete cycle of sliding clamp loading in Escherichia coli.

Autor: Xu ZQ; Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, Australia. zhiqiang@uow.edu.au., Jergic S; Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, Australia., Lo ATY; Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, Australia., Pradhan AC; Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, Australia.; ARC Industrial Transformation Training Centre for Cryo-Electron Microscopy of Membrane Proteins, University of Wollongong, Wollongong, Australia., Brown SHJ; Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, Australia.; ARC Industrial Transformation Training Centre for Cryo-Electron Microscopy of Membrane Proteins, University of Wollongong, Wollongong, Australia., Bouwer JC; Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, Australia.; ARC Industrial Transformation Training Centre for Cryo-Electron Microscopy of Membrane Proteins, University of Wollongong, Wollongong, Australia., Ghodke H; Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, Australia., Lewis PJ; Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, Australia.; Hunter Biological Solutions, Hamilton, Australia., Tolun G; Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, Australia.; ARC Industrial Transformation Training Centre for Cryo-Electron Microscopy of Membrane Proteins, University of Wollongong, Wollongong, Australia., Oakley AJ; Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, Australia., Dixon NE; Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, Australia. nickd@uow.edu.au.; ARC Industrial Transformation Training Centre for Cryo-Electron Microscopy of Membrane Proteins, University of Wollongong, Wollongong, Australia. nickd@uow.edu.au.
Jazyk: angličtina
Zdroj: Nature communications [Nat Commun] 2024 Sep 27; Vol. 15 (1), pp. 8372. Date of Electronic Publication: 2024 Sep 27.
DOI: 10.1038/s41467-024-52623-9
Abstrakt: Ring-shaped DNA sliding clamps are essential for DNA replication and genome maintenance. Clamps need to be opened and chaperoned onto DNA by clamp loader complexes (CLCs). Detailed understanding of the mechanisms by which CLCs open and place clamps around DNA remains incomplete. Here, we present a series of six structures of the Escherichia coli CLC bound to an open or closed clamp prior to and after binding to a primer-template DNA, representing the most significant intermediates in the clamp loading process. We show that the ATP-bound CLC first binds to a clamp, then constricts to hold onto it. The CLC then expands to open the clamp with a gap large enough for double-stranded DNA to enter. Upon binding to DNA, the CLC constricts slightly, allowing clamp closing around DNA. These structures provide critical high-resolution snapshots of clamp loading by the E. coli CLC, revealing how the molecular machine works.
(© 2024. The Author(s).)
Databáze: MEDLINE
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