{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,1]],"date-time":"2026-06-01T13:13:46Z","timestamp":1780319626585,"version":"3.54.1"},"reference-count":42,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2023,7,12]],"date-time":"2023-07-12T00:00:00Z","timestamp":1689120000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000002","name":"National Institutes of Health","doi-asserted-by":"publisher","award":["R35GM133506"],"award-info":[{"award-number":["R35GM133506"]}],"id":[{"id":"10.13039\/100000002","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Cells"],"abstract":"<jats:p>Polyamines are simple yet critical molecules with diverse roles in numerous pathogenic and non-pathogenic organisms. Regulating polyamine concentrations affects the transcription and translation of genes and proteins important for cell growth, stress, and toxicity. One way polyamine concentrations are maintained within the cell is via spermidine\/spermine N-acetyltransferases (SSATs) that acetylate intracellular polyamines so they can be exported. The bacterial SpeG enzyme is an SSAT that exhibits a unique dodecameric structure and allosteric site compared to other SSATs that have been previously characterized. While its overall 3D structure is conserved, its presence and role in different bacterial pathogens are inconsistent. For example, not all bacteria have speG encoded in their genomes; in some bacteria, the speG gene is present but has become silenced, and in other bacteria, it has been acquired on mobile genetic elements. The latter is the case for methicillin-resistant Staphylococcus aureus (MRSA) USA300, where it appears to aid pathogenesis. To gain a greater understanding of the structure\/function relationship of SpeG from the MRSA USA300 strain (SaSpeG), we determined its X-ray crystal structure in the presence and absence of spermine. Additionally, we showed the oligomeric state of SaSpeG is dynamic, and its homogeneity is affected by polyamines and AcCoA. Enzyme kinetic assays showed that pre-incubation with polyamines significantly affected the positive cooperativity toward spermine and spermidine and the catalytic efficiency of the enzyme. Furthermore, we showed bacterial SpeG enzymes do not have equivalent capabilities to acetylate aminopropyl versus aminbutyl ends of spermidine. Overall, this study provides new insight that will assist in understanding the SpeG enzyme and its role in pathogenic and non-pathogenic bacteria at a molecular level.<\/jats:p>","DOI":"10.3390\/cells12141829","type":"journal-article","created":{"date-parts":[[2023,7,13]],"date-time":"2023-07-13T01:52:25Z","timestamp":1689213145000},"page":"1829","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Structural and Kinetic Characterization of the SpeG Spermidine\/Spermine N-acetyltransferase from Methicillin-Resistant Staphylococcus aureus USA300"],"prefix":"10.3390","volume":"12","author":[{"given":"Sofiya","family":"Tsimbalyuk","sequence":"first","affiliation":[{"name":"School of Dentistry and Medical Sciences, Charles Sturt University, Boorooma Street, Wagga Wagga, NSW 2678, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Aleksander","family":"Shornikov","sequence":"additional","affiliation":[{"name":"Deparment of Chemistry and Biochemistry, San Francisco State University, San Francisco, CA 94132, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Parul","family":"Srivastava","sequence":"additional","affiliation":[{"name":"School of Dentistry and Medical Sciences, Charles Sturt University, Boorooma Street, Wagga Wagga, NSW 2678, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Van Thi Bich","family":"Le","sequence":"additional","affiliation":[{"name":"Deparment of Chemistry and Biochemistry, San Francisco State University, San Francisco, CA 94132, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Imani","family":"Warren","sequence":"additional","affiliation":[{"name":"Deparment of Chemistry and Biochemistry, San Francisco State University, San Francisco, CA 94132, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4630-8508","authenticated-orcid":false,"given":"Yogesh B.","family":"Khandokar","sequence":"additional","affiliation":[{"name":"School of Dentistry and Medical Sciences, Charles Sturt University, Boorooma Street, Wagga Wagga, NSW 2678, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7951-9141","authenticated-orcid":false,"given":"Misty L.","family":"Kuhn","sequence":"additional","affiliation":[{"name":"Deparment of Chemistry and Biochemistry, San Francisco State University, San Francisco, CA 94132, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jade K.","family":"Forwood","sequence":"additional","affiliation":[{"name":"School of Dentistry and Medical Sciences, Charles Sturt University, Boorooma Street, Wagga Wagga, NSW 2678, Australia"},{"name":"School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, NSW 2678, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,7,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"629","DOI":"10.1016\/S0140-6736(21)02724-0","article-title":"Global burden of bacterial antimicrobial resistance in 2019: A systematic analysis","volume":"399","author":"Murray","year":"2022","journal-title":"Lancet"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"S71","DOI":"10.1093\/infdis\/jiw444","article-title":"Life After USA300: The Rise and Fall of a Superbug","volume":"215","author":"Planet","year":"2017","journal-title":"J. Infect. Dis."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1523","DOI":"10.1086\/587907","article-title":"The arginine catabolic mobile element and staphylococcal chromosomal cassette mec linkage: Convergence of virulence and resistance in the USA300 clone of methicillin-resistant Staphylococcus aureus","volume":"197","author":"Diep","year":"2008","journal-title":"J. Infect. Dis."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1796","DOI":"10.1093\/jac\/dkac107","article-title":"The bla and mec families of \u03b2-lactam resistance genes in the genera Macrococcus, Mammaliicoccus and Staphylococcus: An in-depth analysis with emphasis on Macrococcus","volume":"77","author":"Schwendener","year":"2022","journal-title":"J. Antimicrob. Chemother."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Uehara, Y. (2022). Current Status of Staphylococcal Cassette Chromosome mec (SCCmec). Antibiotics, 11.","DOI":"10.3390\/antibiotics11010086"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1111\/j.1365-2958.2011.07809.x","article-title":"Arginine catabolic mobile element encoded speG abrogates the unique hypersensitivity of Staphylococcus aureus to exogenous polyamines","volume":"82","author":"Joshi","year":"2011","journal-title":"Mol. Microbiol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"e00889-13","DOI":"10.1128\/mBio.00889-13","article-title":"Emergence of the epidemic methicillin-resistant Staphylococcus aureus strain USA300 coincides with horizontal transfer of the arginine catabolic mobile element and speG-mediated adaptations for survival on skin","volume":"4","author":"Planet","year":"2013","journal-title":"mBio"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"100","DOI":"10.1016\/j.chom.2012.11.012","article-title":"Functional modularity of the arginine catabolic mobile element contributes to the success of USA300 methicillin-resistant Staphylococcus aureus","volume":"13","author":"Thurlow","year":"2013","journal-title":"Cell Host Microbe"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"159","DOI":"10.1111\/mmi.14145","article-title":"Polyamine-independent growth and biofilm formation, and functional spermidine\/spermine N-acetyltransferases in Staphylococcus aureus and Enterococcus faecalis","volume":"111","author":"Li","year":"2019","journal-title":"Mol. Microbiol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2315","DOI":"10.1042\/BCJ20160185","article-title":"Biosynthesis of polyamines and polyamine-containing molecules","volume":"473","author":"Michael","year":"2016","journal-title":"Biochem. J."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"859","DOI":"10.1128\/jb.84.4.859-863.1962","article-title":"Metabolism of polyamines by Staphylococcus","volume":"84","author":"Rosenthal","year":"1962","journal-title":"J. Bacteriol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1099\/00221287-10-1-11","article-title":"Studies on the antibacterial action of spermine","volume":"10","author":"Rozansky","year":"1954","journal-title":"J. Gen. Microbiol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"731","DOI":"10.1016\/S0140-6736(06)68231-7","article-title":"Complete genome sequence of USA300, an epidemic clone of community-acquired meticillin-resistant Staphylococcus aureus","volume":"367","author":"Diep","year":"2006","journal-title":"Lancet"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"616","DOI":"10.1089\/mdr.2016.0176","article-title":"Molecular Characterization of Methicillin-Resistant Staphylococcus aureus from Outpatients in Northern Japan: Increasing Tendency of ST5\/ST764 MRSA-IIa with Arginine Catabolic Mobile Element","volume":"23","author":"Aung","year":"2017","journal-title":"Microb. Drug Resist."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1224","DOI":"10.1128\/AAC.01772-13","article-title":"A novel staphylococcal cassette chromosomal element, SCCfusC, carrying fusC and speG in fusidic acid-resistant methicillin-resistant Staphylococcus aureus","volume":"58","author":"Lin","year":"2014","journal-title":"Antimicrob. Agents Chemother."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2650","DOI":"10.1128\/IAI.00256-09","article-title":"The arginine catabolic mobile element is not associated with enhanced virulence in experimental invasive disease caused by the community-associated methicillin-resistant Staphylococcus aureus USA300 genetic background","volume":"77","author":"Montgomery","year":"2009","journal-title":"Infect. Immun."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Wu, K., Conly, J., McClure, J.-A., Kurwa, H.A., and Zhang, K. (2020). Arginine Catabolic Mobile Element in Evolution and Pathogenicity of the Community-Associated Methicillin-Resistant Staphylococcus aureus Strain USA300. Microorganisms, 8.","DOI":"10.3390\/microorganisms8020275"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"207","DOI":"10.1016\/j.pep.2005.01.016","article-title":"Protein production by auto-induction in high-density shaking cultures","volume":"41","author":"Studier","year":"2005","journal-title":"Protein Expr. Purif."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"271","DOI":"10.1107\/S0907444910048675","article-title":"iMOSFLM: A new graphical interface for diffraction-image processing with MOSFLM","volume":"67","author":"Battye","year":"2011","journal-title":"Acta Crystallogr. D Biol. Crystallogr."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1204","DOI":"10.1107\/S0907444913000061","article-title":"How good are my data and what is the resolution?","volume":"69","author":"Evans","year":"2013","journal-title":"Acta Crystallogr. D Biol. Crystallogr."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"32","DOI":"10.1107\/S0907444906045975","article-title":"Solving structures of protein complexes by molecular replacement with Phaser","volume":"63","author":"McCoy","year":"2007","journal-title":"Acta Crystallogr. D Biol. Crystallogr."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"355","DOI":"10.1107\/S0907444911001314","article-title":"REFMAC5 for the refinement of macromolecular crystal structures","volume":"67","author":"Murshudov","year":"2011","journal-title":"Acta Crystallogr. D Biol. Crystallogr."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"213","DOI":"10.1107\/S0907444909052925","article-title":"PHENIX: A comprehensive Python-based system for macromolecular structure solution","volume":"66","author":"Adams","year":"2010","journal-title":"Acta Crystallogr. D Biol. Crystallogr."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"352","DOI":"10.1107\/S0907444912001308","article-title":"Towards automated crystallographic structure refinement with phenix.refine","volume":"68","author":"Afonine","year":"2012","journal-title":"Acta Crystallogr. D Biol. Crystallogr."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"486","DOI":"10.1107\/S0907444910007493","article-title":"Features and development of Coot","volume":"66","author":"Emsley","year":"2010","journal-title":"Acta Crystallogr. D Biol. Crystallogr."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"645768","DOI":"10.3389\/fmolb.2021.645768","article-title":"The Vibrio cholerae SpeG Spermidine\/Spermine N-Acetyltransferase Allosteric Loop and \u03b26-\u03b27 Structural Elements Are Critical for Kinetic Activity","volume":"8","author":"Le","year":"2021","journal-title":"Front. Mol. Biosci."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"222","DOI":"10.1002\/pro.2199","article-title":"Broad-substrate screen as a tool to identify substrates for bacterial Gcn5-related N-acetyltransferases with unknown substrate specificity","volume":"22","author":"Kuhn","year":"2013","journal-title":"Protein Sci."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1316","DOI":"10.1016\/j.jmb.2015.01.009","article-title":"A novel polyamine allosteric site of SpeG from Vibrio cholerae is revealed by its dodecameric structure","volume":"427","author":"Filippova","year":"2015","journal-title":"J. Mol. Biol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"107506","DOI":"10.1016\/j.jsb.2020.107506","article-title":"SpeG polyamine acetyltransferase enzyme from Bacillus thuringiensis forms a dodecameric structure and exhibits high catalytic efficiency","volume":"210","author":"Tsimbalyuk","year":"2020","journal-title":"J. Struct. Biol."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1264","DOI":"10.1002\/pro.4078","article-title":"Criticality of a conserved tyrosine residue in the SpeG protein from Escherichia coli","volume":"30","author":"Le","year":"2021","journal-title":"Protein Sci."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"22581","DOI":"10.1016\/S0021-9258(17)31685-X","article-title":"Properties and structure of spermidine acetyltransferase in Escherichia coli","volume":"269","author":"Fukuchi","year":"1994","journal-title":"J. Biol. Chem."},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Baskaran, K., Duarte, J.M., Biyani, N., Bliven, S., and Capitani, G. (2014). A PDB-wide, evolution-based assessment of protein-protein interfaces. BMC Struct. Biol., 14.","DOI":"10.1186\/s12900-014-0022-0"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"10881","DOI":"10.1093\/nar\/16.22.10881","article-title":"Multiple sequence alignment with hierarchical clustering","volume":"16","author":"Corpet","year":"1988","journal-title":"Nucleic Acids Res."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"W320","DOI":"10.1093\/nar\/gku316","article-title":"Deciphering key features in protein structures with the new ENDscript server","volume":"42","author":"Robert","year":"2014","journal-title":"Nucleic Acids Res."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"3538","DOI":"10.1016\/j.jmb.2015.09.013","article-title":"Substrate-Induced Allosteric Change in the Quaternary Structure of the Spermidine N-Acetyltransferase SpeG","volume":"427","author":"Filippova","year":"2015","journal-title":"J. Mol. Biol."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"545","DOI":"10.1107\/S2059798319006545","article-title":"Analysis of crystalline and solution states of ligand-free spermidine N-acetyltransferase (SpeG) from Escherichia coli","volume":"75","author":"Filippova","year":"2019","journal-title":"Acta Crystallogr. D Struct. Biol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"271","DOI":"10.1002\/pol.1980.130180406","article-title":"Hydrophobic and polar contributions to solute affinity for a highly crosslinked water-swollen (sephadex) gel","volume":"18","author":"Haglund","year":"1980","journal-title":"J. Polym. Sci. Polym. Lett. Ed."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"163","DOI":"10.1016\/0032-9592(95)00044-5","article-title":"Characteristics of Superdex\u00ae prep grade media for gel filtration chromatography of proteins and peptides","volume":"31","author":"Hellberg","year":"1996","journal-title":"Process Biochem."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"e00216-11","DOI":"10.1128\/mBio.00216-11","article-title":"Biochemical and Thermodynamic Analyses of Salmonella enterica Pat, a Multidomain, Multimeric N-Lysine Acetyltransferase Involved in Carbon and Energy Metabolism","volume":"2","author":"Thao","year":"2011","journal-title":"mBio"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1359","DOI":"10.1002\/pro.2520","article-title":"Double trouble-Buffer selection and His-tag presence may be responsible for nonreproducibility of biomedical experiments","volume":"23","author":"Majorek","year":"2014","journal-title":"Protein Sci."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"02245","DOI":"10.3389\/fmicb.2017.02245","article-title":"speG Is Required for Intracellular Replication of Salmonella in Various Human Cells and Affects Its Polyamine Metabolism and Global Transcriptomes","volume":"8","author":"Fang","year":"2017","journal-title":"Front. Microbiol."},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Jeong, D.-W., Lee, B., Heo, S., Oh, Y., Heo, G., and Lee, J.-H. (2020). Two genes involved in clindamycin resistance of Bacillus licheniformis and Bacillus paralicheniformis identified by comparative genomic analysis. PLoS ONE, 15.","DOI":"10.1371\/journal.pone.0231274"}],"container-title":["Cells"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-4409\/12\/14\/1829\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T20:11:19Z","timestamp":1760127079000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-4409\/12\/14\/1829"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,7,12]]},"references-count":42,"journal-issue":{"issue":"14","published-online":{"date-parts":[[2023,7]]}},"alternative-id":["cells12141829"],"URL":"https:\/\/doi.org\/10.3390\/cells12141829","relation":{},"ISSN":["2073-4409"],"issn-type":[{"value":"2073-4409","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,7,12]]}}}