{"doi":"10.3390/v15020355","title":"Assembly and Capsid Expansion Mechanism of Bacteriophage P22 Revealed by High-Resolution Cryo-EM Structures","abstract":"<jats:p>The formation of many double-stranded DNA viruses, such as herpesviruses and bacteriophages, begins with the scaffolding-protein-mediated assembly of the procapsid. Subsequently, the procapsid undergoes extensive structural rearrangement and expansion to become the mature capsid. Bacteriophage P22 is an established model system used to study virus maturation. Here, we report the cryo-electron microscopy structures of procapsid, empty procapsid, empty mature capsid, and mature capsid of phage P22 at resolutions of 2.6 Å, 3.9 Å, 2.8 Å, and 3.0 Å, respectively. The structure of the procapsid allowed us to build an accurate model of the coat protein gp5 and the C-terminal region of the scaffolding protein gp8. In addition, interactions among the gp5 subunits responsible for procapsid assembly and stabilization were identified. Two C-terminal α-helices of gp8 were observed to interact with the coat protein in the procapsid. The amino acid interactions between gp5 and gp8 in the procapsid were consistent with the results of previous biochemical studies involving mutant proteins. Our structures reveal hydrogen bonds and salt bridges between the gp5 subunits in the procapsid and the conformational changes of the gp5 domains involved in the closure of the local sixfold opening and a thinner capsid shell during capsid maturation.</jats:p>","journal":"Viruses","year":2023,"id":673904,"datarank":0.4943755299006494,"base_score":3.295836866004329,"endowment":3.295836866004329,"self_citation_contribution":0.4943755299006494,"citation_network_contribution":0.0,"self_endowment_contribution":0.4943755299006494,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":26,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":null,"is_data_producer":false,"deposit_databanks":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":null,"fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1760746,"name":"Junquan Zhou","orcid":null,"position":1,"is_corresponding":false},{"id":1294743,"name":"Fan Yang","orcid":"0000-0003-3671-4745","position":2,"is_corresponding":false},{"id":426564,"name":"Zheng Liu","orcid":"0000-0002-0405-2348","position":3,"is_corresponding":false},{"id":6080,"name":"Jingdong Song","orcid":"0000-0001-8808-1981","position":4,"is_corresponding":false},{"id":923864,"name":"Wenyuan Chen","orcid":"0000-0002-9449-8596","position":5,"is_corresponding":false},{"id":1760747,"name":"Hongrong Liu","orcid":null,"position":6,"is_corresponding":false},{"id":1760748,"name":"Lingpeng Cheng","orcid":null,"position":7,"is_corresponding":false},{"id":1760745,"name":"Hao Xiao","orcid":null,"position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"resolved":true,"title":"Assembly and Capsid Expansion Mechanism of Bacteriophage P22 Revealed by High-Resolution Cryo-EM Structures","abstract":"<jats:p>The formation of many double-stranded DNA viruses, such as herpesviruses and bacteriophages, begins with the scaffolding-protein-mediated assembly of the procapsid. Subsequently, the procapsid undergoes extensive structural rearrangement and expansion to become the mature capsid. Bacteriophage P22 is an established model system used to study virus maturation. Here, we report the cryo-electron microscopy structures of procapsid, empty procapsid, empty mature capsid, and mature capsid of phage P22 at resolutions of 2.6 Å, 3.9 Å, 2.8 Å, and 3.0 Å, respectively. The structure of the procapsid allowed us to build an accurate model of the coat protein gp5 and the C-terminal region of the scaffolding protein gp8. In addition, interactions among the gp5 subunits responsible for procapsid assembly and stabilization were identified. Two C-terminal α-helices of gp8 were observed to interact with the coat protein in the procapsid. The amino acid interactions between gp5 and gp8 in the procapsid were consistent with the results of previous biochemical studies involving mutant proteins. Our structures reveal hydrogen bonds and salt bridges between the gp5 subunits in the procapsid and the conformational changes of the gp5 domains involved in the closure of the local sixfold opening and a thinner capsid shell during capsid maturation.</jats:p>","is_dataset_classified":null,"base_score":3.295836866004329,"endowment":3.295836866004329,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"36851569","pmcid":"PMC9965877","openalex_id":"https://openalex.org/W4318206839","authors":[],"funders":[{"funder_name":"National Natural Science Foundation of China","grant_id":"12034006","title":null},{"funder_name":"National Natural Science Foundation of China","grant_id":"31971122","title":null},{"funder_name":"National Natural Science Foundation of China","grant_id":"32071209","title":null},{"funder_name":"National Natural Science Foundation of China","grant_id":"32200994","title":null}],"total_grants":4,"fwci":5.076,"citation_percentile":0.95617277,"influential_citations":0,"citation_trend":[{"year":2023,"count":5},{"year":2024,"count":10},{"year":2025,"count":9},{"year":2026,"count":2}],"oa_status":"gold","license":"cc-by","oa_locations":[{"url":"https://www.mdpi.com/1999-4915/15/2/355/pdf?version=1674733382","host_type":"journal"},{"url":"https://www.mdpi.com/1999-4915/15/2/355/pdf?version=1674733382","host_type":"publisher"},{"url":"https://www.mdpi.com/1999-4915/15/2/355/pdf","host_type":"publisher"},{"url":"https://doi.org/10.3390/v15020355","host_type":"journal"},{"url":"https://pubmed.ncbi.nlm.nih.gov/36851569","host_type":"repository"},{"url":"https://www.ncbi.nlm.nih.gov/pmc/articles/9965877","host_type":"repository"},{"url":"https://doaj.org/article/f4b9b4c1ef2142239e0765bd158b7d5e","host_type":"repository"},{"url":"https://dx.doi.org/10.3390/v15020355","host_type":"repository"},{"url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC9965877/pdf/viruses-15-00355.pdf","host_type":"repository"},{"url":"https://europepmc.org/articles/PMC9965877","host_type":"Europe_PMC"},{"url":"https://europepmc.org/articles/PMC9965877?pdf=render","host_type":"Europe_PMC"}],"fields_of_study":["Bacteriophages and microbial interactions","RNA and protein synthesis mechanisms","Genomics and Phylogenetic Studies"],"mesh_terms":["Bacteriophages","Capsid","Bacteriophage P22","Cryoelectron Microscopy","Capsid Proteins"],"keywords":["Capsid","Bacteriophage","Scaffold protein","Biophysics","Filamentous bacteriophage","Protein structure","Capsomere","Chemistry","Crystallography","Biology","Cell biology","Virus","Virology","Biochemistry","Escherichia coli","virus assembly","Scaffolding Protein","Cryo-em","Bacteriophage P22","Capsid Expansion"],"sdg_mappings":[],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[{"name":"pdb"}],"source":"live","citation_network_status":"fetched"},"created_at":"2026-08-16T14:51:50.847090Z","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":[]}