{"doi":"10.7554/elife.55517","title":"Cryo-EM structure in situ reveals a molecular switch that safeguards virus against genome loss","abstract":"The portal protein is a key component of many double-stranded DNA viruses, governing capsid assembly and genome packaging. Twelve subunits of the portal protein define a tunnel, through which DNA is translocated into the capsid. It is unknown how the portal protein functions as a gatekeeper, preventing DNA slippage, whilst allowing its passage into the capsid, and how these processes are controlled. A cryo-EM structure of the portal protein of thermostable virus P23-45, determined in situ in its procapsid-bound state, indicates a mechanism that naturally safeguards the virus against genome loss. This occurs via an inversion of the conformation of the loops that define the constriction in the central tunnel, accompanied by a hydrophilic-hydrophobic switch. The structure also shows how translocation of DNA into the capsid could be modulated by a changing mode of protein-protein interactions between portal and capsid, across a symmetry-mismatched interface.","journal":"eLife","year":2020,"id":101426,"datarank":1.0440913333088475,"base_score":3.332204510175204,"endowment":3.332204510175204,"self_citation_contribution":0.49983067652628066,"citation_network_contribution":0.544260656782567,"self_endowment_contribution":0.49983067652628066,"citer_contribution":0.544260656782567,"corpus_percentile":null,"corpus_rank":null,"citation_count":27,"citer_count":22,"citers_with_citation_signal":18,"citers_with_endowment":18,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9492,"is_data_producer":true,"deposit_databanks":{"PDB":["6QJT"]},"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2020-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":382778,"name":"Alasdair C. Steven","orcid":"0000-0003-4104-6497","position":1,"is_corresponding":false},{"id":106085,"name":"Alfred A. Antson","orcid":"0000-0002-4533-3816","position":2,"is_corresponding":false},{"id":106086,"name":"Oliver W. Bayfield","orcid":"0000-0003-1421-7780","position":0,"is_corresponding":true}],"reference_count":43,"raw_metadata":null,"created_at":"2026-07-18T22:39:38.259162Z","pmid":"32286226","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":[]}