{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,7]],"date-time":"2026-02-07T17:40:52Z","timestamp":1770486052470,"version":"3.49.0"},"reference-count":33,"publisher":"American Society for Microbiology","issue":"9","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J. Bacteriol."],"published-print":{"date-parts":[[2015,5,1]]},"abstract":"<jats:title>ABSTRACT<\/jats:title><jats:p>Cyclic \u03b2-1,2-glucans (C\u03b2G) are periplasmic homopolysaccharides that play an important role in the virulence and interaction of<jats:named-content content-type=\"genus-species\">Brucella<\/jats:named-content>with the host. Once synthesized in the cytoplasm by the C\u03b2G synthase (Cgs), C\u03b2G are transported to the periplasm by the C\u03b2G transporter (Cgt) and succinylated by the C\u03b2G modifier enzyme (Cgm). Here, we used a bacterial two-hybrid system and coimmunoprecipitation techniques to study the interaction network between these three integral inner membrane proteins. Our results indicate that Cgs, Cgt, and Cgm can form both homotypic and heterotypic interactions. Analyses carried out with Cgs mutants revealed that the N-terminal region of the protein (Cgs region 1 to 418) is required to sustain the interactions with Cgt and Cgm as well as with itself. We demonstrated by single-cell fluorescence analysis that in<jats:named-content content-type=\"genus-species\">Brucella<\/jats:named-content>, Cgs and Cgt are focally distributed in the membrane, particularly at the cell poles, whereas Cgm is mostly distributed throughout the membrane with a slight accumulation at the poles colocalizing with the other partners. In summary, our results demonstrate that Cgs, Cgt, and Cgm form a membrane-associated biosynthetic complex. We propose that the formation of a membrane complex could serve as a mechanism to ensure the fidelity of C\u03b2G biosynthesis by coordinating their synthesis with the transport and modification.<\/jats:p><jats:p><jats:bold>IMPORTANCE<\/jats:bold>In this study, we analyzed the interaction and localization of the proteins involved in the synthesis, transport, and modification of<jats:named-content content-type=\"genus-species\">Brucella abortus<\/jats:named-content>cyclic \u03b2-1,2-glucans (C\u03b2G), which play an important role in the virulence and interaction of<jats:named-content content-type=\"genus-species\">Brucella<\/jats:named-content>with the host. We demonstrate that these proteins interact, forming a complex located mainly at the cell poles; this is the first experimental evidence of the existence of a multienzymatic complex involved in the metabolism of osmoregulated periplasmic glucans in bacteria and argues for another example of pole differentiation in<jats:named-content content-type=\"genus-species\">Brucella<\/jats:named-content>. We propose that the formation of this membrane complex could serve as a mechanism to ensure the fidelity of C\u03b2G biosynthesis by coordinating synthesis with the transport and modification.<\/jats:p>","DOI":"10.1128\/jb.00068-15","type":"journal-article","created":{"date-parts":[[2015,3,3]],"date-time":"2015-03-03T03:23:47Z","timestamp":1425353027000},"page":"1640-1648","source":"Crossref","is-referenced-by-count":20,"title":["Interaction Network and Localization of Brucella abortus Membrane Proteins Involved in the Synthesis, Transport, and Succinylation of Cyclic \u03b2-1,2-Glucans"],"prefix":"10.1128","volume":"197","author":[{"given":"Leticia S.","family":"Guidolin","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Susana M.","family":"Morrone Seijo","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Francisco F.","family":"Guaimas","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Diego J.","family":"Comerci","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Andr\u00e9s E.","family":"Ciocchini","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"235","published-online":{"date-parts":[[2015,3,2]]},"reference":[{"key":"key20180919081454_B1","doi-asserted-by":"publisher","first-page":"11","DOI":"10.1111\/j.1574-6968.2000.tb09075.x","article-title":"Osmoregulated periplasmic glucans in Proteobacteria","volume":"186","year":"2000","journal-title":"FEMS Microbiol Lett"},{"key":"key20180919081454_B2","doi-asserted-by":"crossref","first-page":"145","DOI":"10.1128\/MMBR.58.2.145-161.1994","article-title":"Cyclic beta-glucans of members of the family Rhizobiaceae","volume":"58","year":"1994","journal-title":"Microbiol 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J.","family":"Christie","sequence":"additional","affiliation":[],"role":[{"role":"editor","vocabulary":"crossref"}]}],"short-title":[],"issued":{"date-parts":[[2015,3,2]]},"references-count":33,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2015,4,6]]},"published-print":{"date-parts":[[2015,5,1]]}},"alternative-id":["10.1128\/JB.00068-15"],"URL":"https:\/\/doi.org\/10.1128\/jb.00068-15","relation":{},"ISSN":["0021-9193","1098-5530"],"issn-type":[{"value":"0021-9193","type":"print"},{"value":"1098-5530","type":"electronic"}],"subject":[],"published":{"date-parts":[[2015,3,2]]}}}