{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,5]],"date-time":"2026-10-05T20:12:30Z","timestamp":1791231150303,"version":"4.1.0"},"reference-count":55,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2021,12,16]],"date-time":"2021-12-16T00:00:00Z","timestamp":1639612800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000266","name":"EPSRC","doi-asserted-by":"publisher","award":["EP\/N031962\/1"],"award-info":[{"award-number":["EP\/N031962\/1"]}],"id":[{"id":"10.13039\/501100000266","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Microbiol."],"abstract":"<jats:p>Partitioning proteins are well studied as molecular organizers of chromosome and plasmid segregation during division, however little is known about the roles partitioning proteins can play within type IV secretion systems. The single-stranded DNA (ssDNA)-secreting gonococcal T4SS has two partitioning proteins, ParA and ParB. These proteins work in collaboration with the relaxase TraI as essential facilitators of type IV secretion. Bacterial two-hybrid experiments identified interactions between each partitioning protein and the relaxase. Subcellular fractionation demonstrated that ParA is found in the cellular membrane, whereas ParB is primarily in the membrane, but some of the protein is in the soluble fraction. Since TraI is known to be membrane-associated, these data suggest that the gonococcal relaxosome is a membrane-associated complex. In addition, we found that translation of ParA and ParB is controlled by an RNA switch. Different mutations within the stem-loop sequence predicted to alter folding of this RNA structure greatly increased or decreased levels of the partitioning proteins.<\/jats:p>","DOI":"10.3389\/fmicb.2021.784483","type":"journal-article","created":{"date-parts":[[2021,12,16]],"date-time":"2021-12-16T16:16:43Z","timestamp":1639671403000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":8,"title":["Expression, Localization, and Protein Interactions of the Partitioning Proteins in the Gonococcal Type IV Secretion System"],"prefix":"10.3389","volume":"12","author":[{"given":"Melanie M.","family":"Callaghan","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Birgit","family":"Koch","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kathleen T.","family":"Hackett","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Amy K.","family":"Klimowicz","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ryan E.","family":"Schaub","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Natalio","family":"Krasnogor","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Joseph P.","family":"Dillard","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2021,12,16]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"403","DOI":"10.1016\/S0022-2836(05)80360-2","article-title":"Basic local alignment search tool","volume":"215","author":"Altschul","year":"1990","journal-title":"J. Mol. Biol."},{"key":"ref2","doi-asserted-by":"publisher","first-page":"775","DOI":"10.1128\/MMBR.00023-09","article-title":"Biological diversity of prokaryotic type IV secretion systems","volume":"73","author":"Alvarez-Martinez","year":"2009","journal-title":"Microbiol. Mol. Biol. Rev."},{"key":"ref3","article-title":"User Bulletin #2 Relative Quantitation of Gene Expression Introduction. Foster City, CA","year":"1997"},{"key":"ref4","doi-asserted-by":"publisher","first-page":"2540","DOI":"10.1038\/sj.emboj.7601696","article-title":"Agrobacterium ParA\/MinD-like VirC1 spatially coordinates early conjugative DNA transfer reactions","volume":"26","author":"Atmakuri","year":"2007","journal-title":"EMBO J."},{"key":"ref5","doi-asserted-by":"publisher","first-page":"2406","DOI":"10.1099\/mic.0.081216-0","article-title":"Dissection of the region of Pseudomonas aeruginosa ParA that is important for dimerization and interactions with its partner ParB","volume":"160","author":"Bartosik","year":"2014","journal-title":"Microbiology"},{"key":"ref6","doi-asserted-by":"publisher","first-page":"325","DOI":"10.1016\/j.ymeth.2012.07.018","article-title":"The bacterial two-hybrid system based on adenylate cyclase reconstitution in Escherichia coli","volume":"58","author":"Battesti","year":"2012","journal-title":"Methods"},{"key":"ref7","doi-asserted-by":"publisher","first-page":"W465","DOI":"10.1093\/nar\/gkp363","article-title":"TOPCONS: consensus prediction of membrane protein topology","volume":"37","author":"Bernsel","year":"2009","journal-title":"Nucleic Acids Res."},{"key":"ref8","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1016\/S0168-1656(01)00293-0","article-title":"The bacterial ParA-ParB partitioning proteins","volume":"91","author":"Bignell","year":"2001","journal-title":"J. Biotechnol."},{"key":"ref9","doi-asserted-by":"publisher","first-page":"143","DOI":"10.1007\/978-1-4939-9496-0_10","article-title":"Transformation in Neisseria gonorrhoeae","volume":"1997","author":"Callaghan","year":"2019","journal-title":"Methods Mol. Biol."},{"key":"ref10","first-page":"323","article-title":"Secretion of chromosomal DNA by the Neisseria gonorrhoeae type IV secretion system","volume-title":"Current Topics in Microbiology and Immunology: Type IV Secretion in Gram-Negative and Gram-Positive Bacteria.","author":"Callaghan","year":"2017"},{"key":"ref11","doi-asserted-by":"publisher","first-page":"e0051921","DOI":"10.1128\/IAI.00519-21","article-title":"Transcriptional and translational responsiveness of the Neisseria gonorrhoeae type IV secretion system to conditions of host infections","volume":"89","author":"Callaghan","year":"2021","journal-title":"Infect. Immun."},{"key":"ref12","article-title":"Sexually Transmitted Disease Surveillance 2018. Atlanta, Georgia","year":"2019"},{"key":"ref13","article-title":"Sexually Transmitted Disease Surveillance 2019: Gonococcal Isolate Surveillance Project (GISP) Supplement & Profiles. Atlanta, Georgia","year":"2021"},{"key":"ref14","doi-asserted-by":"publisher","first-page":"1029","DOI":"10.1111\/j.1365-2958.2008.06210.x","article-title":"Control of the cell elongation-division cycle by shuttling of PBP1 protein in Bacillus subtilis","volume":"68","author":"Claessen","year":"2008","journal-title":"Mol. Microbiol."},{"key":"ref15","doi-asserted-by":"publisher","first-page":"263","DOI":"10.1046\/j.1365-2958.2001.02520.x","article-title":"A variable genetic island specific for Neisseria gonorrhoeae is involved in providing DNA for natural transformation and is found more often in disseminated infection isolates","volume":"41","author":"Dillard","year":"2001","journal-title":"Mol. Microbiol."},{"key":"ref16","doi-asserted-by":"publisher","first-page":"D427","DOI":"10.1093\/nar\/gky995","article-title":"The Pfam protein families database in 2019","volume":"47","author":"El-Gebali","year":"2019","journal-title":"Nucleic Acids Res."},{"key":"ref17","doi-asserted-by":"publisher","first-page":"1619","DOI":"10.1101\/gr.278202","article-title":"CDART: protein homology by domain architecture","volume":"12","author":"Geer","year":"2002","journal-title":"Genome Res."},{"key":"ref18","doi-asserted-by":"publisher","first-page":"32","DOI":"10.3389\/fmolb.2016.00032","article-title":"Conjugative DNA transfer is enhanced by plasmid R1 partitioning proteins","volume":"3","author":"Gruber","year":"2016","journal-title":"Front. Mol. Biosci."},{"key":"ref19","doi-asserted-by":"publisher","first-page":"315","DOI":"10.1093\/molbev\/mss221","article-title":"Evolution of conjugation and type IV secretion systems","volume":"30","author":"Guglielmini","year":"2013","journal-title":"Mol. Biol. Evol."},{"key":"ref20","doi-asserted-by":"publisher","first-page":"376","DOI":"10.1111\/j.1365-2958.2005.04964.x","article-title":"Natural transformation of Neisseria gonorrhoeae: from DNA donation to homologous recombination","volume":"59","author":"Hamilton","year":"2006","journal-title":"Mol. Microbiol."},{"key":"ref21","doi-asserted-by":"publisher","first-page":"1704","DOI":"10.1111\/j.1365-2958.2005.04521.x","article-title":"Neisseria gonorrhoeae secretes chromosomal DNA via a novel type IV secretion system","volume":"55","author":"Hamilton","year":"2005","journal-title":"Mol. Microbiol."},{"key":"ref22","doi-asserted-by":"publisher","first-page":"4718","DOI":"10.1128\/JB.183.16.4718-4726.2001","article-title":"Insertion-duplication mutagenesis of Neisseria: use in characterization of DNA transfer genes in the gonococcal genetic island","volume":"183","author":"Hamilton","year":"2001","journal-title":"J. Bacteriol."},{"key":"ref23","doi-asserted-by":"publisher","first-page":"740","DOI":"10.1038\/35047123","article-title":"A toll-like receptor recognizes bacterial DNA","volume":"408","author":"Hemmi","year":"2000","journal-title":"Nature"},{"key":"ref24","doi-asserted-by":"publisher","first-page":"e35285","DOI":"10.1371\/journal.pone.0035285","article-title":"Characterization of the single stranded DNA binding protein SsbB encoded in the gonoccocal genetic island","volume":"7","author":"Jain","year":"2012","journal-title":"PLoS One"},{"key":"ref25","doi-asserted-by":"publisher","first-page":"420","DOI":"10.1038\/s41587-019-0036-z","article-title":"SignalP 5.0 improves signal peptide predictions using deep neural networks","volume":"37","author":"Juan","year":"2019","journal-title":"Nat. Biotechnol."},{"key":"ref26","first-page":"73","article-title":"Protein-protein interaction between Bacillus stearothermophilus tyrosyl-tRNA synthetase subdomains revealed by a bacterial two-hybrid system","volume":"3","author":"Karimova","year":"2001","journal-title":"J. Mol. Microbiol. Biotechnol."},{"key":"ref27","doi-asserted-by":"publisher","first-page":"1274","DOI":"10.1128\/jb.85.6.1274-1279.1963","article-title":"Neisseria gonorrhoeae. I. virulence genetically linked to clonal variation","volume":"85","author":"Kellogg","year":"1963","journal-title":"J. Bacteriol."},{"key":"ref28","doi-asserted-by":"publisher","first-page":"518","DOI":"10.1128\/JB.186.2.518-534.2004","article-title":"Sequence analysis of the mobile genome island pKLC102 of Pseudomonas aeruginosa C","volume":"186","author":"Klockgether","year":"2004","journal-title":"J. Bacteriol."},{"key":"ref29","doi-asserted-by":"publisher","first-page":"823","DOI":"10.1111\/mmi.14582","article-title":"Protein interactions within and between two F-type type IV secretion systems","volume":"114","author":"Koch","year":"2020","journal-title":"Mol. Microbiol."},{"key":"ref30","doi-asserted-by":"publisher","first-page":"1666","DOI":"10.1128\/JB.02098-12","article-title":"Mating pair formation homologue TraG is a variable membrane protein essential for contact-independent type IV secretion of chromosomal DNA by Neisseria gonorrhoeae","volume":"195","author":"Kohler","year":"2013","journal-title":"J. Bacteriol."},{"key":"ref31","doi-asserted-by":"publisher","first-page":"675","DOI":"10.1016\/S0092-8674(00)81135-6","article-title":"Identification and characterization of a bacterial chromosome partitioning site","volume":"92","author":"Lin","year":"1998","journal-title":"Cell"},{"key":"ref32","doi-asserted-by":"publisher","first-page":"237","DOI":"10.1038\/nature12616","article-title":"Temperature triggers immune evasion by Neisseria meningitidis","volume":"502","author":"Loh","year":"2013","journal-title":"Nature"},{"key":"ref33","doi-asserted-by":"publisher","first-page":"411","DOI":"10.1016\/j.tim.2012.05.002","article-title":"The ParA\/MinD family puts things in their place","volume":"20","author":"Lutkenhaus","year":"2012","journal-title":"Trends Microbiol."},{"key":"ref34","doi-asserted-by":"publisher","first-page":"D200","DOI":"10.1093\/nar\/gkw1129","article-title":"CDD\/SPARCLE: functional classification of proteins via subfamily domain architectures","volume":"45","author":"Marchler-Bauer","year":"2017","journal-title":"Nucleic Acids Res."},{"key":"ref35","doi-asserted-by":"publisher","first-page":"2005","DOI":"10.1099\/mic.0.000369","article-title":"Loop structures in the 5\u2032 untranslated region and antisense RNA mediate pilE gene expression in Neisseria gonorrhoeae","volume":"162","author":"Masters","year":"2016","journal-title":"Microbiology"},{"key":"ref36","doi-asserted-by":"publisher","first-page":"3686","DOI":"10.1128\/JB.01890-06","article-title":"A novel Fur- and iron-regulated small RNA, NrrF, is required for indirect Fur-mediated regulation of the sdhA and sdhC genes in Neisseria meningitidis","volume":"189","author":"Mellin","year":"2007","journal-title":"J. Bacteriol."},{"key":"ref37","volume-title":"Experiments in Molecular Genetics.","author":"Miller","year":"1972"},{"key":"ref38","doi-asserted-by":"publisher","first-page":"1418","DOI":"10.3181\/00379727-145-38025","article-title":"Factors affecting autolysis of Neisseria gonorrhoeae","volume":"145","author":"Morse","year":"1974","journal-title":"Proc. Soc. Exp. Biol. Med."},{"key":"ref39","doi-asserted-by":"publisher","first-page":"2650","DOI":"10.1101\/gad.552209","article-title":"A pH-responsive riboregulator","volume":"23","author":"Nechooshtan","year":"2009","journal-title":"Genes Dev."},{"key":"ref40","doi-asserted-by":"publisher","first-page":"e109613","DOI":"10.1371\/journal.pone.0109613","article-title":"Functional analysis of the gonococcal genetic island of Neisseria gonorrhoeae","volume":"9","author":"Pachulec","year":"2014","journal-title":"PLoS One"},{"key":"ref41","doi-asserted-by":"publisher","first-page":"873","DOI":"10.1038\/nbt1110","article-title":"Complete genome sequence of the plant commensal Pseudomonas fluorescens Pf-5","volume":"23","author":"Paulsen","year":"2005","journal-title":"Nat. Biotechnol."},{"key":"ref42","doi-asserted-by":"publisher","first-page":"1168","DOI":"10.1111\/mmi.13094","article-title":"Targeted mutagenesis of intergenic regions in the Neisseria gonorrhoeae gonococcal genetic island reveals multiple regulatory mechanisms controlling type IV secretion","volume":"97","author":"Ramsey","year":"2015","journal-title":"Mol. Microbiol."},{"key":"ref43","doi-asserted-by":"publisher","first-page":"2954","DOI":"10.1128\/JB.01825-14","article-title":"TraK and TraB are conserved outer membrane proteins of the Neisseria gonorrhoeae type IV secretion system and are expressed at low levels in wild-type cells","volume":"196","author":"Ramsey","year":"2014","journal-title":"J. Bacteriol."},{"key":"ref44","doi-asserted-by":"publisher","first-page":"3068","DOI":"10.1128\/AEM.07871-11","article-title":"New complementation constructs for inducible and constitutive gene expression in Neisseria gonorrhoeae and Neisseria meningitidis","volume":"78","author":"Ramsey","year":"2012","journal-title":"Appl. Environ. Microbiol."},{"key":"ref45","doi-asserted-by":"publisher","first-page":"10579","DOI":"10.1093\/nar\/gku762","article-title":"Transcriptional landscape and essential genes of Neisseria gonorrhoeae","volume":"42","author":"Remmele","year":"2014","journal-title":"Nucleic Acids Res."},{"key":"ref46","doi-asserted-by":"publisher","first-page":"930","DOI":"10.1111\/j.1365-2958.2007.05966.x.A","article-title":"A novel relaxase homologue is involved in chromosomal DNA processing for type IV secretion in Neisseria gonorrhoeae","volume":"66","author":"Salgado-Pab\u00f3n","year":"2007","journal-title":"Mol. Microbiol."},{"key":"ref47","doi-asserted-by":"publisher","first-page":"516","DOI":"10.1038\/nature04149","article-title":"Structures of ParB bound to DNA reveal mechanism of partition complex formation","volume":"438","author":"Schumacher","year":"2005","journal-title":"Nature"},{"key":"ref48","doi-asserted-by":"publisher","first-page":"361","DOI":"10.1146\/annurev-micro-091014-104306","article-title":"Riboswitch-mediated gene regulation: novel RNA architectures dictate gene expression responses","volume":"70","author":"Sherwood","year":"2016","journal-title":"Annu. Rev. Microbiol."},{"key":"ref49","article-title":"Genomics of Bacterial Pathogens across Evolutionary Scales. Ph.D. thesis. University of Wisconsin-Madison","author":"Shockey","year":"2019"},{"key":"ref50","doi-asserted-by":"publisher","first-page":"1258","DOI":"10.1084\/jem.136.5.1258","article-title":"Studies on gonococcus infection II: freeze-fracture, freeze-etch studies on gonococci","volume":"136","author":"Swanson","year":"1972","journal-title":"J. Exp. Med."},{"key":"ref51","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1038\/srep02935","article-title":"Evaluation of a new high-throughput method for identifying quorum quenching bacteria","volume":"3","author":"Tang","year":"2013","journal-title":"Sci. Rep."},{"key":"ref52","doi-asserted-by":"publisher","first-page":"346","DOI":"10.1007\/BF00538693","article-title":"ATPase activity of SopA, a protein essential for active partitioning of F plasmid","volume":"234","author":"Watanabe","year":"1992","journal-title":"Mol. Gen. Genet."},{"key":"ref53","doi-asserted-by":"publisher","first-page":"487","DOI":"10.1146\/annurev.micro.59.030804.121336","article-title":"Regulation of bacterial gene expression by riboswitches","volume":"59","author":"Winkler","year":"2005","journal-title":"Annu. Rev. Microbiol."},{"key":"ref54","doi-asserted-by":"publisher","first-page":"2180","DOI":"10.1128\/JB.00166-16","article-title":"Characterization of the Neisseria gonorrhoeae iron and Fur regulatory network","volume":"198","author":"Yu","year":"2016","journal-title":"J. Bacteriol."},{"key":"ref55","doi-asserted-by":"publisher","first-page":"85","DOI":"10.1186\/1471-2105-7-85","article-title":"Statistical analysis of real-time PCR data","volume":"7","author":"Yuan","year":"2006","journal-title":"BMC Bioinform."}],"container-title":["Frontiers in Microbiology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fmicb.2021.784483\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,12,16]],"date-time":"2021-12-16T16:16:50Z","timestamp":1639671410000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fmicb.2021.784483\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,12,16]]},"references-count":55,"alternative-id":["10.3389\/fmicb.2021.784483"],"URL":"https:\/\/doi.org\/10.3389\/fmicb.2021.784483","relation":{},"ISSN":["1664-302X"],"issn-type":[{"value":"1664-302X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,12,16]]},"article-number":"784483"}}