{"doi":"10.1101/2021.09.13.460164","title":"Mechanisms of loading and release of the 9-1-1 checkpoint clamp","abstract":"Abstract 5’ single-stranded/double-stranded DNA serve as loading sites for the checkpoint clamp, 9-1-1, which mediates activation of the apical checkpoint kinase, ATR Mec1 . However, the basis for 9-1-1’s recruitment to 5’ junctions is unclear. Here, we present structures of the yeast checkpoint clamp loader, Rad24-RFC, in complex with 9-1-1 and a 5’ junction and in a post-ATP-hydrolysis state. Unexpectedly, 9-1-1 adopts both closed and planar open states in the presence of Rad24-RFC and DNA. Moreover, Rad24-RFC associates with the DNA junction in the opposite orientation of processivity clamp loaders with Rad24 exclusively coordinating the double-stranded region. ATP hydrolysis stimulates conformational changes in Rad24-RFC, leading to disengagement of DNA-loaded 9-1-1. Together, these structures explain 9-1-1’s recruitment to 5’ junctions and reveal new principles of sliding clamp loading.","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":2021,"id":216835,"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":4,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9556,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":300701,"name":"Marina Schrecker","orcid":"0000-0001-8542-6657","position":1,"is_corresponding":false},{"id":609023,"name":"Dirk Remus","orcid":"0000-0002-5155-181X","position":2,"is_corresponding":false},{"id":292045,"name":"Richard K. Hite","orcid":"0000-0003-0496-0669","position":3,"is_corresponding":false},{"id":813194,"name":"Juan C. Castaneda","orcid":"0000-0003-0622-7831","position":0,"is_corresponding":true}],"reference_count":37,"raw_metadata":null,"created_at":"2026-07-18T23:53:15.868165Z","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":[]}