{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T17:01:07Z","timestamp":1790787667258,"version":"4.1.0"},"reference-count":50,"publisher":"National Academy of Sciences","issue":"40","license":[{"start":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T00:00:00Z","timestamp":1790726400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000002","name":"HHS | NIH","doi-asserted-by":"publisher","award":["R35 GM131817"],"award-info":[{"award-number":["R35 GM131817"]}],"id":[{"id":"10.13039\/100000002","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000002","name":"HHS | NIH","doi-asserted-by":"publisher","award":["T32 GM008505"],"award-info":[{"award-number":["T32 GM008505"]}],"id":[{"id":"10.13039\/100000002","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000002","name":"HHS | NIH","doi-asserted-by":"publisher","award":["T32 GM152341"],"award-info":[{"award-number":["T32 GM152341"]}],"id":[{"id":"10.13039\/100000002","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000001","name":"NSF","doi-asserted-by":"publisher","award":["DGE-2137424"],"award-info":[{"award-number":["DGE-2137424"]}],"id":[{"id":"10.13039\/100000001","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000001","name":"NSF","doi-asserted-by":"publisher","award":["BIR-9512577"],"award-info":[{"award-number":["BIR-9512577"]}],"id":[{"id":"10.13039\/100000001","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000002","name":"HHS | NIH","doi-asserted-by":"publisher","award":["S10 RR13790"],"award-info":[{"award-number":["S10 RR13790"]}],"id":[{"id":"10.13039\/100000002","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["www.pnas.org"],"crossmark-restriction":true},"short-container-title":["Proc. Natl. Acad. Sci. U.S.A."],"published-print":{"date-parts":[[2026,10,6]]},"abstract":"<jats:p>\n                    Quorum sensing (QS) enables common gram-negative bacteria to coordinate collective behaviors through small molecule signals, yet how these signals tune receptor activity remains incompletely understood. Here, we define a mechanism by which ligand structure controls function in a LuxR-type QS receptor. Using structural and biochemical analyses, we investigate MrtR from\n                    <jats:italic toggle=\"yes\">Mesorhizobium tianshanense<\/jats:italic>\n                    and show that ligand acyl-chain length governs receptor assembly and activity. We present full-length structures of MrtR bound to activating and inhibitory ligands, revealing a switch in oligomeric state. Long-chain (C14)\n                    <jats:italic toggle=\"yes\">N<\/jats:italic>\n                    -acyl\n                    <jats:sc>l<\/jats:sc>\n                    -homoserine lactones (AHLs) act as agonists by promoting intra- and intersubunit interactions that lead to homodimerization and DNA binding. In contrast, shorter (C8) AHLs fail to promote these contacts, favoring a monomeric, inactive state. Ligands of intermediate length produce graded responses consistent with partial dimer stabilization. Biochemical measurements of DNA binding, thermostability, and oligomerization, together with targeted mutagenesis, support this model and establish the functional importance of key structural contacts. These findings provide a side-by-side structural comparison of a full-length LuxR-type receptor bound to both agonist and antagonist. Our results expand the known structural and mechanistic diversity of the LuxR family and suggest mechanistic similarities between structurally distinct receptors.\n                  <\/jats:p>","DOI":"10.1073\/pnas.2616692123","type":"journal-article","created":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T16:13:32Z","timestamp":1790784812000},"update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":0,"title":["MrtR of\n                    <i>Mesorhizobium tianshanense<\/i>\n                    reveals both activation and inhibition mechanisms of a LuxR-type quorum sensing receptor"],"prefix":"10.1073","volume":"123","author":[{"given":"Irene M.","family":"Stoutland","sequence":"first","affiliation":[{"id":[{"id":"https:\/\/ror.org\/01y2jtd41","id-type":"ROR","asserted-by":"publisher"}],"name":"Department of Chemistry, University of Wisconsin\u2013Madison","place":["Madison"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4261-8194","authenticated-orcid":false,"given":"Helen E.","family":"Blackwell","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/01y2jtd41","id-type":"ROR","asserted-by":"publisher"}],"name":"Department of Chemistry, University of Wisconsin\u2013Madison","place":["Madison"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"341","published-online":{"date-parts":[[2026,9,30]]},"reference":[{"key":"e_1_3_4_1_2","doi-asserted-by":"publisher","DOI":"10.1038\/nature24624"},{"key":"e_1_3_4_2_2","doi-asserted-by":"publisher","DOI":"10.1128\/MMBR.00024-14"},{"key":"e_1_3_4_3_2","doi-asserted-by":"publisher","DOI":"10.1038\/nrmicro.2016.89"},{"key":"e_1_3_4_4_2","doi-asserted-by":"publisher","DOI":"10.1021\/cr100064s"},{"key":"e_1_3_4_5_2","doi-asserted-by":"publisher","DOI":"10.1093\/femsre\/fuw009"},{"key":"e_1_3_4_6_2","doi-asserted-by":"publisher","DOI":"10.1007\/s00253-010-2521-7"},{"key":"e_1_3_4_7_2","doi-asserted-by":"publisher","DOI":"10.1039\/b412802h"},{"key":"e_1_3_4_8_2","doi-asserted-by":"publisher","DOI":"10.1016\/S1074-5521(03)00002-4"},{"key":"e_1_3_4_9_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.0608348103"},{"key":"e_1_3_4_10_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja903292v"},{"key":"e_1_3_4_11_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.1316981110"},{"key":"e_1_3_4_12_2","doi-asserted-by":"publisher","DOI":"10.1021\/acsinfecdis.9b00518"},{"key":"e_1_3_4_13_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.molcel.2011.04.003"},{"key":"e_1_3_4_14_2","doi-asserted-by":"publisher","DOI":"10.1074\/jbc.M700556200"},{"key":"e_1_3_4_15_2","doi-asserted-by":"publisher","DOI":"10.1099\/mic.0.001343"},{"key":"e_1_3_4_16_2","doi-asserted-by":"publisher","DOI":"10.1038\/srep21383"},{"key":"e_1_3_4_17_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0022-2836(05)80360-2"},{"key":"e_1_3_4_18_2","doi-asserted-by":"publisher","DOI":"10.1128\/JB.188.5.1943-1949.2006"},{"key":"e_1_3_4_19_2","doi-asserted-by":"publisher","DOI":"10.1046\/j.1365-2958.2003.03699.x"},{"key":"e_1_3_4_20_2","doi-asserted-by":"publisher","DOI":"10.1128\/JB.184.16.4510-4519.2002"},{"key":"e_1_3_4_21_2","doi-asserted-by":"publisher","DOI":"10.1074\/jbc.M106655200"},{"key":"e_1_3_4_22_2","doi-asserted-by":"publisher","DOI":"10.1128\/JB.00003-15"},{"key":"e_1_3_4_23_2","doi-asserted-by":"publisher","DOI":"10.1128\/JB.01247-08"},{"key":"e_1_3_4_24_2","first-page":"e00407","article-title":"RefAHL: A curated quorum sensing reference linking diverse LuxI-type signal synthases with their acyl-homoserine lactone products","volume":"14","author":"Schaefer A. L.","year":"2025","unstructured":"A. L. Schaefer , RefAHL: A curated quorum sensing reference linking diverse LuxI-type signal synthases with their acyl-homoserine lactone products. Microbiol. Resour. Announce. 14, e00407\u2013e00425 (2025).","journal-title":"Microbiol. Resour. Announce."},{"key":"e_1_3_4_25_2","doi-asserted-by":"crossref","unstructured":"I. M. Stoutland S. A. Walker H. E. Blackwell Domain-swapped LuxR-type quorum sensing receptors reveal divergent ligand-response mechanisms among homologues. J. Am. Chem. Soc. 148 38256\u201338270 (2026).","DOI":"10.1021\/jacs.6c11050"},{"key":"e_1_3_4_26_2","doi-asserted-by":"publisher","DOI":"10.1021\/cb300351x"},{"key":"e_1_3_4_27_2","doi-asserted-by":"publisher","DOI":"10.1128\/JB.01041-10"},{"key":"e_1_3_4_28_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.chroma.2006.07.017"},{"key":"e_1_3_4_29_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41586-024-07487-w"},{"key":"e_1_3_4_30_2","doi-asserted-by":"publisher","DOI":"10.1093\/emboj\/cdf459"},{"key":"e_1_3_4_31_2","doi-asserted-by":"publisher","DOI":"10.1128\/mBio.02429-14"},{"key":"e_1_3_4_32_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41467-022-35030-w"},{"key":"e_1_3_4_33_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jmb.2007.05.022"},{"key":"e_1_3_4_34_2","doi-asserted-by":"publisher","DOI":"10.1038\/nature00833"},{"key":"e_1_3_4_35_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.str.2022.10.008"},{"key":"e_1_3_4_36_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.1112398108"},{"key":"e_1_3_4_37_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.chembiol.2018.06.007"},{"key":"e_1_3_4_38_2","doi-asserted-by":"publisher","DOI":"10.1111\/mmi.13930"},{"key":"e_1_3_4_39_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.98.4.1507"},{"key":"e_1_3_4_40_2","doi-asserted-by":"publisher","DOI":"10.1128\/JB.186.3.631-637.2004"},{"key":"e_1_3_4_41_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.ppat.1007820"},{"key":"e_1_3_4_42_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.1817239116"},{"key":"e_1_3_4_43_2","unstructured":"Chai Discovery Chai-1: Decoding the molecular interactions of life. bioRxiv [Preprint] (2024). 10.1101\/2024.10.10.615955 (Accessed 16 September 2026)."},{"key":"e_1_3_4_44_2","doi-asserted-by":"publisher","DOI":"10.1098\/rstb.2007.2041"},{"key":"e_1_3_4_45_2","doi-asserted-by":"publisher","DOI":"10.1107\/S2059798323003595"},{"key":"e_1_3_4_46_2","doi-asserted-by":"crossref","unstructured":"I. M. Stoutland A.R. Buller C.A. Bingman H. E. Blackwell Crystal structure of MrtR bound to 7Z-3OH-C14 homoserine lactone. Protein Data Bank. https:\/\/doi.org\/10.2210\/pdb9Y2H\/pdb. Deposited 1 September 2025.","DOI":"10.2210\/pdb9y2h\/pdb"},{"key":"e_1_3_4_47_2","doi-asserted-by":"crossref","unstructured":"I. M. Stoutland C.A. Bingman H. E. Blackwell Crystal structure of MrtR bound to 3OH-C14 homoserine lactone. Protein Data Bank. https:\/\/doi.org\/10.2210\/pdb9ZZ0\/pdb. Deposited 5 January 2026.","DOI":"10.2210\/pdb9zz0\/pdb"},{"key":"e_1_3_4_48_2","doi-asserted-by":"crossref","unstructured":"I. M. Stoutland C.A. Bingman H. E. Blackwell Crystal structure of MrtR bound to 3OH-C8 homoserine lactone. Protein Data Bank. https:\/\/doi.org\/10.2210\/pdb9ZPJ\/pdb. Deposited 15 December 2025.","DOI":"10.2210\/pdb9zpj\/pdb"},{"key":"e_1_3_4_49_2","doi-asserted-by":"crossref","unstructured":"I. M. Stoutland C.A. Bingman H. E. Blackwell Crystal structure of MrtR bound to 3O-C8 homoserine lactone. Protein Data Bank. https:\/\/doi.org\/10.2210\/pdb11BM\/pdb. Deposited 15 December 2025.","DOI":"10.2210\/pdb9zpj\/pdb"},{"key":"e_1_3_4_50_2","doi-asserted-by":"crossref","unstructured":"I. M. Stoutland C.A. Bingman H. E. Blackwell Crystal structure of MrtR bound to 3O-C8 homoserine lactone and tetraethylene glycol. Protein Data Bank. https:\/\/doi.org\/10.2210\/pdb10ZI\/pdb. Deposited 11 February 2026.","DOI":"10.2210\/pdb10zi\/pdb"}],"container-title":["Proceedings of the National Academy of Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pnas.org\/doi\/pdf\/10.1073\/pnas.2616692123","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/pnas.org\/doi\/pdf\/10.1073\/pnas.2616692123","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T16:14:40Z","timestamp":1790784880000},"score":1,"resource":{"primary":{"URL":"https:\/\/pnas.org\/doi\/10.1073\/pnas.2616692123"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,30]]},"references-count":50,"journal-issue":{"issue":"40","published-print":{"date-parts":[[2026,10,6]]}},"alternative-id":["10.1073\/pnas.2616692123"],"URL":"https:\/\/doi.org\/10.1073\/pnas.2616692123","relation":{},"ISSN":["0027-8424","1091-6490"],"issn-type":[{"value":"0027-8424","type":"print"},{"value":"1091-6490","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,30]]},"assertion":[{"value":"2026-05-11","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-08-28","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-09-30","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e2616692123"}}