{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,29]],"date-time":"2026-07-29T16:30:09Z","timestamp":1785342609034,"version":"3.55.0"},"reference-count":48,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2017,12,16]],"date-time":"2017-12-16T00:00:00Z","timestamp":1513382400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000002","name":"The National Institutes of Health","doi-asserted-by":"publisher","award":["R01 AI083255"],"award-info":[{"award-number":["R01 AI083255"]}],"id":[{"id":"10.13039\/100000002","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Viruses"],"abstract":"<jats:p>In the tailed bacteriophages, DNA is packaged into spherical procapsids, leading to expansion into angular, thin-walled mature capsids. In many cases, this maturation is accompanied by cleavage of the major capsid protein (CP) and other capsid-associated proteins, including the scaffolding protein (SP) that serves as a chaperone for the assembly process. Staphylococcus aureus bacteriophage 80\u03b1 is capable of high frequency mobilization of mobile genetic elements called S. aureus pathogenicity islands (SaPIs), such as SaPI1. SaPI1 redirects the assembly pathway of 80\u03b1 to form capsids that are smaller than those normally made by the phage alone. Both CP and SP of 80\u03b1 are N-terminally processed by a host-encoded protease, Prp. We have analyzed phage mutants that express pre-cleaved or uncleavable versions of CP or SP, and show that the N-terminal sequence in SP is absolutely required for assembly, but does not need to be cleaved in order to produce viable capsids. Mutants with pre-cleaved or uncleavable CP display normal viability. We have used cryo-EM to solve the structures of mature capsids from an 80\u03b1 mutant expressing uncleavable CP, and from wildtype SaPI1. Comparisons with structures of 80\u03b1 and SaPI1 procapsids show that capsid maturation involves major conformational changes in CP, consistent with a release of the CP N-arm by SP. The hexamers reorganize during maturation to accommodate the different environments in the 80\u03b1 and SaPI1 capsids.<\/jats:p>","DOI":"10.3390\/v9120384","type":"journal-article","created":{"date-parts":[[2017,12,19]],"date-time":"2017-12-19T03:54:32Z","timestamp":1513655672000},"page":"384","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":21,"title":["Cleavage and Structural Transitions during Maturation of Staphylococcus aureus Bacteriophage 80\u03b1 and SaPI1 Capsids"],"prefix":"10.3390","volume":"9","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2608-8595","authenticated-orcid":false,"given":"James","family":"Kizziah","sequence":"first","affiliation":[{"name":"Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Keith","family":"Manning","sequence":"additional","affiliation":[{"name":"Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Altaira","family":"Dearborn","sequence":"additional","affiliation":[{"name":"Protein Expression Laboratory, National Institute of Arthritis and Musculoskeletal and Skin Diseases, The National Institutes of Health, Bethesda, MD 20892, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Erin","family":"Wall","sequence":"additional","affiliation":[{"name":"Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA 23298, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Laura","family":"Klenow","sequence":"additional","affiliation":[{"name":"Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA 23298, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rosanne","family":"Hill","sequence":"additional","affiliation":[{"name":"Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michael","family":"Spilman","sequence":"additional","affiliation":[{"name":"Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8855-4152","authenticated-orcid":false,"given":"Scott","family":"Stagg","sequence":"additional","affiliation":[{"name":"Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gail","family":"Christie","sequence":"additional","affiliation":[{"name":"Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA 23298, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Terje","family":"Dokland","sequence":"additional","affiliation":[{"name":"Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2017,12,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1179","DOI":"10.1086\/520289","article-title":"Staphylococcus aureus: A well-armed pathogen","volume":"26","author":"Archer","year":"1998","journal-title":"Clin. Infect. Dis."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"520","DOI":"10.1056\/NEJM199808203390806","article-title":"Staphylococcus aureus infections","volume":"339","author":"Lowy","year":"1998","journal-title":"N. Eng. J. Med."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1557","DOI":"10.1016\/S0140-6736(09)61999-1","article-title":"Community-associated meticillin-resistant Staphylococcus aureus","volume":"375","author":"DeLeo","year":"2010","journal-title":"Lancet"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"S344","DOI":"10.1086\/533590","article-title":"Epidemiology of methicillin-resistant Staphylococcus aureus","volume":"46","author":"Boucher","year":"2008","journal-title":"Clin. Infect. Dis."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"3057","DOI":"10.1007\/s00018-010-0389-4","article-title":"Mobile genetic elements of Staphylococcus aureus","volume":"67","author":"Malachowa","year":"2010","journal-title":"Cell. Mol. Life Sci."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1146\/annurev.micro.112408.134309","article-title":"Basis of virulence in community-associated methicillin-resistant Staphylococcus aureus","volume":"64","author":"Otto","year":"2010","journal-title":"Annu. Rev. Microbiol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"103","DOI":"10.1016\/j.ijmm.2013.11.010","article-title":"Staphylococcus aureus genomics and the impact of horizontal gene transfer","volume":"304","author":"Lindsay","year":"2014","journal-title":"Int. J. Med. Microbiol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"155","DOI":"10.1016\/0042-6822(67)90105-5","article-title":"Properties of a cryptic high-frequency transducing phage in Staphylococcus aureus","volume":"33","author":"Novick","year":"1967","journal-title":"Virology"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"381","DOI":"10.1016\/j.virol.2010.08.036","article-title":"The complete genomes of Staphylococcus aureus bacteriophages 80 and 80\u03b1\u2014Implications for the specificity of SaPI mobilization","volume":"407","author":"Christie","year":"2010","journal-title":"Virology"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"863","DOI":"10.1016\/j.jmb.2010.11.047","article-title":"A conformational switch involved in maturation of Staphylococcus aureus bacteriophage 80\u03b1 capsids","volume":"405","author":"Spilman","year":"2011","journal-title":"J. Mol. Biol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"465","DOI":"10.1016\/j.jmb.2008.04.065","article-title":"Capsid size determination by Staphylococcus aureus pathogenicity island SaPI1 involves specific incorporation of SaPI1 proteins into procapsids","volume":"380","author":"Poliakov","year":"2008","journal-title":"J. Mol. Biol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"258","DOI":"10.1111\/mmi.12862","article-title":"Specific N-terminal cleavage of ribosomal protein L27 in Staphylococcus aureus and related bacteria","volume":"95","author":"Wall","year":"2015","journal-title":"Mol. Microbiol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"520","DOI":"10.1111\/mmi.13644","article-title":"Structural modeling and functional analysis of the essential ribosomal processing protease Prp from Staphylococcus aureus","volume":"104","author":"Wall","year":"2017","journal-title":"Mol. Microbiol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"541","DOI":"10.1038\/nrmicro2393","article-title":"The phage-related chromosomal islands of Gram-positive bacteria","volume":"8","author":"Novick","year":"2010","journal-title":"Nat. Rev. Microbiol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"210","DOI":"10.1016\/j.virol.2012.10.028","article-title":"Pirates of the Caudovirales","volume":"434","author":"Christie","year":"2012","journal-title":"Virology"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"779","DOI":"10.1038\/nature09065","article-title":"Moonlighting bacteriophage proteins derepress staphylococcal pathogenicity islands","volume":"465","author":"Mir","year":"2010","journal-title":"Nature"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"70","DOI":"10.4161\/bact.20632","article-title":"Mobilization of pathogenicity islands by Staphylococcus aureus strain Newman bacteriophages","volume":"2","author":"Dearborn","year":"2012","journal-title":"Bacteriophage"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"142","DOI":"10.1016\/j.jmb.2015.11.009","article-title":"The type 2 dUTPase of bacteriophage \u03c6NM1 initiates mobilization of Staphylococcus aureus bovine pathogenicity island 1","volume":"428","author":"Hill","year":"2016","journal-title":"J. Mol. Biol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"e26487","DOI":"10.7554\/eLife.26487","article-title":"Pirating conserved phage mechanisms promotes promiscuous staphylococcal pathogenicity island transfer","volume":"6","author":"Bowring","year":"2017","journal-title":"eLife"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"277","DOI":"10.1016\/j.virol.2012.05.026","article-title":"The roles of SaPI1 proteins gp7 (CpmA) and gp6 (CpmB) in capsid size determination and helper phage interference","volume":"432","author":"Damle","year":"2012","journal-title":"Virology"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"710","DOI":"10.1016\/j.jmb.2011.07.036","article-title":"The Staphylococcus aureus pathogenicity island protein gp6 functions as an internal scaffold during capsid size determination","volume":"412","author":"Dearborn","year":"2011","journal-title":"J. Mol. Biol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"e30822","DOI":"10.7554\/eLife.30822","article-title":"Competing scaffolding proteins determine capsid size during mobilization of Staphylococcus aureus pathogenicity islands","volume":"6","author":"Dearborn","year":"2017","journal-title":"eLife"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1016\/j.plasmid.2013.12.001","article-title":"Sequence determinants for DNA packaging specificity in the S. aureus pathogenicity island SaPI1","volume":"71","author":"Bento","year":"2014","journal-title":"Plasmid"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"6887","DOI":"10.1128\/AEM.70.11.6887-6891.2004","article-title":"New vector for efficient allelic replacement in naturally nontransformable, low-GC-content, gram-positive bacteria","volume":"70","author":"Arnaud","year":"2004","journal-title":"Appl. Environ. Microbiol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"587","DOI":"10.1016\/0076-6879(91)04029-N","article-title":"Genetic systems in Staphylococci","volume":"204","author":"Novick","year":"1991","journal-title":"Methods Enzymol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"709","DOI":"10.1038\/305709a0","article-title":"The toxic shock syndrome exotoxin structural gene is not detectably transmitted by a prophage","volume":"305","author":"Kreiswirth","year":"1983","journal-title":"Nature"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"98","DOI":"10.1111\/j.1365-2958.2009.06634.x","article-title":"Specificity of staphylococcal phage and SaPI DNA packaging as revealed by integrase and terminase mutations","volume":"72","author":"Ubeda","year":"2009","journal-title":"Mol. Microbiol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"2434","DOI":"10.1128\/JB.01349-07","article-title":"SaPI DNA is packaged in particles composed of phage proteins","volume":"190","author":"Tormo","year":"2008","journal-title":"J. Bacteriol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"242","DOI":"10.1016\/j.virol.2012.08.031","article-title":"Assembly of bacteriophage 80\u03b1 capsids in a Staphylococcus aureus expression system","volume":"434","author":"Spilman","year":"2012","journal-title":"Virology"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"41","DOI":"10.1016\/j.jsb.2005.03.010","article-title":"Automated molecular microscopy: The new Leginon system","volume":"151","author":"Suloway","year":"2005","journal-title":"J. Struct. Biol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1016\/j.jsb.2009.01.002","article-title":"Appion: An integrated, database-driven pipeline to facilitate EM image processing","volume":"166","author":"Lander","year":"2009","journal-title":"J. Struct. Biol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"205","DOI":"10.1016\/j.jsb.2009.01.004","article-title":"DoG Picker and TiltPicker: Software tools to facilitate particle selection in single particle electron microscopy","volume":"166","author":"Voss","year":"2009","journal-title":"J. Struct. Biol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"91","DOI":"10.1016\/j.jsb.2003.11.007","article-title":"FindEM\u2014A fast, efficient program for automatic selection of particles from electron micrographs","volume":"145","author":"Roseman","year":"2004","journal-title":"J. Struct. Biol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1016\/j.ultramic.2005.02.004","article-title":"ACE: Automated CTF estimation","volume":"104","author":"Mallick","year":"2005","journal-title":"Ultramicroscopy"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"401","DOI":"10.1007\/978-1-62703-776-1_19","article-title":"Single particle cryo-electron microscopy and 3-D reconstruction of viruses","volume":"1117","author":"Guo","year":"2014","journal-title":"Methods Mol. Biol."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"136","DOI":"10.1107\/S1399004714021683","article-title":"Tools for macromolecular model building and refinement into electron cryo-microscopy reconstructions","volume":"71","author":"Brown","year":"2015","journal-title":"Acta Crystallogr. D Biol. Crystallogr."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"82","DOI":"10.1006\/jsbi.1999.4174","article-title":"EMAN: Semiautomated software for high-resolution single-partice reconstructions","volume":"128","author":"Ludtke","year":"1999","journal-title":"J. Struct. Biol."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"73","DOI":"10.1016\/j.jsb.2006.08.007","article-title":"AUTO3DEM\u2014An automated and high throughput program for image reconstruction of icosahedral particles","volume":"157","author":"Yan","year":"2007","journal-title":"J. Struct. Biol."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1016\/j.jsb.2006.06.006","article-title":"Bsoft: Image processing and molecular modeling for electron microscopy","volume":"157","author":"Heymann","year":"2007","journal-title":"J. Struct. Biol."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1605","DOI":"10.1002\/jcc.20084","article-title":"UCSF Chimera\u2014A visualization system for exploratory research and analysis","volume":"25","author":"Pettersen","year":"2004","journal-title":"J. Comput. Chem."},{"key":"ref_41","first-page":"69","article-title":"Structure and assembly of bacteriophage lambda","volume":"78","author":"Hohn","year":"1977","journal-title":"Curr. Top. Microbiol. Immunol."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"697","DOI":"10.1016\/0022-2836(73)90205-2","article-title":"Mechanism of head assembly and DNA encapsulation in Salmonella phage P22. II. Morphogenetic pathway","volume":"80","author":"King","year":"1973","journal-title":"J. Mol. Biol."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"86","DOI":"10.1006\/jmbi.1995.0538","article-title":"Proteolytic and conformational control of virus capsid maturation: The bacteriophage HK97 system","volume":"253","author":"Conway","year":"1995","journal-title":"J. Mol. Biol."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"210","DOI":"10.1016\/j.sbi.2010.01.004","article-title":"Virus particle maturation: Insights into elegantly programmed nanomachines","volume":"20","author":"Johnson","year":"2010","journal-title":"Curr. Opin. Struct. Biol."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"192","DOI":"10.1128\/jvi.53.1.192-197.1985","article-title":"Autoregulation of the bacteriophage P22 scaffolding protein gene","volume":"53","author":"Wyckoff","year":"1985","journal-title":"J. Virol."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"839","DOI":"10.1002\/j.1460-2075.1992.tb05121.x","article-title":"Image reconstruction from cryo-electron micrographs reveals the morphopoietic mechanism in the P2\u2013P4 bacteriophage system","volume":"11","author":"Dokland","year":"1992","journal-title":"EMBO J."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"215","DOI":"10.1016\/j.jsb.2012.04.002","article-title":"Structure and size determination of bacteriophage P2 and P4 procapsids: Function of size responsiveness mutations","volume":"178","author":"Dearborn","year":"2012","journal-title":"J. Struct. Biol."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"2559","DOI":"10.1016\/S0006-3495(93)81313-4","article-title":"Pattern formation in icosahedral virus capsids: The papova viruses and Nudaurelia capensis \u03b2 virus","volume":"65","author":"Marzec","year":"1993","journal-title":"Biophys. J."}],"container-title":["Viruses"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1999-4915\/9\/12\/384\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T18:54:17Z","timestamp":1760208857000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1999-4915\/9\/12\/384"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,12,16]]},"references-count":48,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2017,12]]}},"alternative-id":["v9120384"],"URL":"https:\/\/doi.org\/10.3390\/v9120384","relation":{},"ISSN":["1999-4915"],"issn-type":[{"value":"1999-4915","type":"electronic"}],"subject":[],"published":{"date-parts":[[2017,12,16]]}}}