{"database":"biostudies-literature","file_versions":[],"scores":null,"additional":{"submitter":["Arimura Y"],"funding":["Stavros Niarchos Foundation","Osamu Hayaishi Memorial Scholarship","National Institute of General Medical Sciences","NIGMS NIH HHS","Japan Society for the Promotion of Science"],"pagination":["RP103486"],"full_dataset_link":["https://www.ebi.ac.uk/biostudies/studies/S-EPMC12092007"],"repository":["biostudies-literature"],"omics_type":["Unknown"],"volume":["13"],"pubmed_abstract":["Cryo-EM single-particle analyses typically require target macromolecule concentration at 0.05~5.0 mg/ml, which is often difficult to achieve. Here, we devise <i>Ma</i><u>g</u>netic <i>I</i>solation and <i>C</i>oncentration (MagIC)-cryo-EM, a technique enabling direct structural analysis of targets captured on magnetic beads, thereby reducing the targets' concentration requirement to <0.0005 mg/mL. Adapting MagIC-cryo-EM to a Chromatin Immunoprecipitation protocol, we characterized structural variations of the linker histone H1.8-associated nucleosomes that were isolated from interphase and metaphase chromosomes in <i>Xenopus</i> egg extract. Combining <i>Du</i>plicated <i>S</i>election <i>T</i>o <i>E</i>xclude <i>R</i>ubbish particles (DuSTER), a particle curation method that excludes low signal-to-noise ratio particles, we also resolved the 3D cryo-EM structures of nucleoplasmin NPM2 co-isolated with the linker histone H1.8 and revealed distinct open and closed structural variants. Our study demonstrates the utility of MagIC-cryo-EM for structural analysis of scarce macromolecules in heterogeneous samples and provides structural insights into the cell cycle-regulation of H1.8 association to nucleosomes."],"journal":["eLife"],"pubmed_title":["MagIC-Cryo-EM, structural determination on magnetic beads for scarce macromolecules in heterogeneous samples."],"pmcid":["PMC12092007"],"funding_grant_id":["SNF Institute for Global Infectious Disease Research","Overseas Research Fellowships","Scholarship for Study Abroad","R35 GM132111","R35GM132111"],"pubmed_authors":["Funabiki H","Arimura Y","Konishi HA"],"additional_accession":[]},"is_claimable":false,"name":"MagIC-Cryo-EM, structural determination on magnetic beads for scarce macromolecules in heterogeneous samples.","description":"Cryo-EM single-particle analyses typically require target macromolecule concentration at 0.05~5.0 mg/ml, which is often difficult to achieve. Here, we devise <i>Ma</i><u>g</u>netic <i>I</i>solation and <i>C</i>oncentration (MagIC)-cryo-EM, a technique enabling direct structural analysis of targets captured on magnetic beads, thereby reducing the targets' concentration requirement to <0.0005 mg/mL. Adapting MagIC-cryo-EM to a Chromatin Immunoprecipitation protocol, we characterized structural variations of the linker histone H1.8-associated nucleosomes that were isolated from interphase and metaphase chromosomes in <i>Xenopus</i> egg extract. Combining <i>Du</i>plicated <i>S</i>election <i>T</i>o <i>E</i>xclude <i>R</i>ubbish particles (DuSTER), a particle curation method that excludes low signal-to-noise ratio particles, we also resolved the 3D cryo-EM structures of nucleoplasmin NPM2 co-isolated with the linker histone H1.8 and revealed distinct open and closed structural variants. Our study demonstrates the utility of MagIC-cryo-EM for structural analysis of scarce macromolecules in heterogeneous samples and provides structural insights into the cell cycle-regulation of H1.8 association to nucleosomes.","dates":{"release":"2025-01-01T00:00:00Z","publication":"2025 May","modification":"2026-06-01T14:56:34.663Z","creation":"2026-04-08T13:32:32.593Z"},"accession":"S-EPMC12092007","cross_references":{"pubmed":["40390365"],"doi":["10.7554/eLife.103486"]}}