{"doi":"10.1101/2023.04.30.538894","title":"Structural Insights into γH2Ax containing Nucleosomes","abstract":"Abstract MDC1 is a key mediator of DNA-damage signaling. When DNA double-strand breaks (DSB) occur, the histone variant H2AX on the nucleosome is phosphorylated on its C-terminus at residue Ser139 to form the γH2AX nucleosome. This phosphorylated form is specifically recognized by the tandem BRCT repeats of MDC1. The MDC1-bound nucleosome serves as a docking platform to promote the localization of other DNA repair factors. To further characterize the nucleosome-BRCT interaction, we developed a time efficient two-step modified native chemical ligation protocol to prepare phosphorylated nucleosomes. Our binding studies show that BRCT interacts with the nucleosome with a higher affinity than the phosphorylated peptide. Using cryogenic electron microscopy (cryo-EM), we obtained structures of the γH2AX nucleosome revealing the structural basis for nucleosome-nucleosome stacking promoted by interactions of the H4 N-terminal of one nucleosome with its stacked partner. In contrast, we show that binding of the MDC1 BRCT domain disrupts this stacking, suggesting that histone/DNA dynamics are integral to DNA damage signaling.","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":2023,"id":406812,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":0,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9505,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2023-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1186142,"name":"Ross A. Edwards","orcid":null,"position":1,"is_corresponding":false},{"id":1185918,"name":"Md. Touhidul Islam","orcid":"0000-0003-3206-0326","position":2,"is_corresponding":false},{"id":1172684,"name":"Jun Lu","orcid":"0000-0002-1699-8835","position":3,"is_corresponding":false},{"id":1168271,"name":"Ayodeji Kulepa","orcid":null,"position":4,"is_corresponding":false},{"id":250981,"name":"Tae‐Hwan Kim","orcid":"0000-0002-3542-2276","position":5,"is_corresponding":false},{"id":933743,"name":"J. N. Mark Glover","orcid":"0000-0003-2733-7052","position":6,"is_corresponding":false},{"id":968726,"name":"Rashmi Panigrahi","orcid":"0000-0002-1727-9269","position":0,"is_corresponding":true}],"reference_count":41,"raw_metadata":null,"created_at":"2026-07-19T01:21:07.213041Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}