Work

Visualization of the complete preprimosome reveals the structural mechanisms governing DNA replication restart

Year: 2026

Type: article

Abstract: Replication restart pathways reinitiate DNA replication processes following their premature termination. In Escherichia coli , this essential process begins with regulated assembly of the preprimosome complex, comprising the PriA, PriB, and DnaT proteins, onto an abandoned replication fork. Here, we present two distinct preprimosome structures. One represents an intermediate stage in preprimosome assembly with a single DnaT C-terminal domain (DnaT CTD ) bound to PriA/PriB/DNA. The second captures the mature preprimosome, in which filamentation of multiple DnaT CTD molecules catalyzes the handoff of the single-stranded lagging-strand DNA from PriB to DnaT. The DnaT N-terminal domain forms a separate, independent oligomer in the mature structure. Taken together, our results detail the molecular mechanisms underlying replication restart initiation and regulation and suggest mechanistic similarities between DnaT and the canonical initiator protein DnaA.

Source: Nature Communications

DOI: 10.1038/s41467-026-73239-1

Authors: Peter L. Ducos, Alexander T. Duckworth, Kenneth A. Satyshur, James L. Keck, Timothy Grant

Institutions: University of Wisconsin–Madison, Morgridge Institute for Research

Language: English

Topic: Bacterial Genetics and Biotechnology

Subfield: Genetics

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: gold

Estimated APC paid: $6,990

Funders: National Institutes of Health, National Institute of General Medical Sciences