{"doi":"10.15252/embj.2019103787","title":"DNA asymmetry promotes SUMO modification of the single‐stranded DNA‐binding protein RPA","abstract":"Repair of DNA double‐stranded breaks by homologous recombination (HR) is dependent on DNA end resection and on post‐translational modification of repair factors. In budding yeast, single‐stranded DNA is coated by replication protein A (RPA) following DNA end resection, and DNA–RPA complexes are then SUMO‐modified by the E3 ligase Siz2 to promote repair. Here, we show using enzymatic assays that DNA duplexes containing 3' single‐stranded DNA overhangs increase the rate of RPA SUMO modification by Siz2. The SAP domain of Siz2 binds DNA duplexes and makes a key contribution to this process as highlighted by models and a crystal structure of Siz2 and by assays performed using protein mutants. Enzymatic assays performed using DNA that can accommodate multiple RPA proteins suggest a model in which the SUMO‐RPA signal is amplified by successive rounds of Siz2‐dependent SUMO modification of RPA and dissociation of SUMO‐RPA at the junction between single‐ and double‐stranded DNA. Our results provide insights on how DNA architecture scaffolds a substrate and E3 ligase to promote SUMO modification in the context of DNA repair. DNA damage elicits protein group modification by SUMO of factors involved in mediating DNA repair and homologous recombination. The SUMO E3 ligase Siz2 is central to this response and is required for efficient SUMO modification of Replication Protein A (RPA) when bound to single stranded DNA. Structural and biochemical studies of the yeast SUMO E3 ligase Siz2 offer insight into the molecular basis of DNA damage‐triggered SUMO group modification.","journal":"The EMBO Journal","year":2021,"id":197399,"datarank":0.622230284295088,"base_score":2.639057329615259,"endowment":2.639057329615259,"self_citation_contribution":0.3958585994422889,"citation_network_contribution":0.22637168485279913,"self_endowment_contribution":0.3958585994422889,"citer_contribution":0.22637168485279913,"corpus_percentile":null,"corpus_rank":null,"citation_count":13,"citer_count":12,"citers_with_citation_signal":9,"citers_with_endowment":9,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9555,"is_data_producer":true,"deposit_databanks":{"PDB":["6U75"]},"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":771371,"name":"Tomasz Kochańczyk","orcid":"0000-0002-4989-8064","position":1,"is_corresponding":false},{"id":742256,"name":"Christopher D. Lima","orcid":"0000-0002-9163-6092","position":2,"is_corresponding":false},{"id":771370,"name":"Laurent Cappadocia","orcid":"0000-0001-7348-1982","position":0,"is_corresponding":true}],"reference_count":55,"raw_metadata":null,"created_at":"2026-07-18T23:50:23.532351Z","pmid":"34585421","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":[]}