Reconstitution of human DNA licensing and the structural and functional analysis of key intermediates.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 39779677.
- Also identified by DOI 10.1038/s41467-024-55772-z and PMC identifier 11711466.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Human DNA licensing initiates replication fork assembly and DNA replication. This reaction promotes the loading of the hMCM2-7 complex on DNA, which represents the core of the replicative helicase that unwinds DNA during S-phase. Here, we report the reconstitution of human DNA licensing using purified proteins. We showed that the in vitro reaction is specific and results in the assembly of high-salt resistant hMCM2-7 double-hexamers. With ATPγS, an hORC1-5-hCDC6-hCDT1-hMCM2-7 (hOCCM) assembles independent of hORC6, but hORC6 enhances double-hexamer formation. We determined the hOCCM structure, which showed that hORC-hCDC6 recruits hMCM2-7 via five hMCM winged-helix domains. The structure highlights how hORC1 activates the hCDC6 ATPase and uncovered an unexpected role for hCDC6 ATPase in complex disassembly. We identified that hCDC6 binding to hORC1-5 stabilises hORC2-DNA interactions and supports hMCM3-dependent recruitment of hMCM2-7. Finally, the structure allowed us to locate cancer-associated mutations at the hCDC6-hMCM3 interface, which showed specific helicase loading defects.
Medical subject headings
- DNA
- DNA Replication
- Minichromosome Maintenance Complex Component 7
- Minichromosome Maintenance Complex Component 2
- Origin Recognition Complex
- Cell Cycle Proteins
- Nuclear Proteins