{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T09:08:02Z","timestamp":1790759282867,"version":"4.1.0"},"reference-count":38,"publisher":"National Academy of Sciences","issue":"18","content-domain":{"domain":["www.pnas.org"],"crossmark-restriction":true},"short-container-title":["Proc. Natl. Acad. Sci. U.S.A."],"published-print":{"date-parts":[[2011,5,3]]},"abstract":"<jats:p>\n                    Cobalamin (B\n                    <jats:sub>12<\/jats:sub>\n                    ) typically functions as an enzyme cofactor but can also regulate gene expression via RNA-based riboswitches. B\n                    <jats:sub>12<\/jats:sub>\n                    -directed gene regulatory mechanisms via protein factors have, however, remained elusive. Recently, we reported down-regulation of a light-inducible promoter in the bacterium\n                    <jats:italic>Myxococcus xanthus<\/jats:italic>\n                    by two paralogous transcriptional repressors, of which one, CarH, but not the other, CarA, absolutely requires B\n                    <jats:sub>12<\/jats:sub>\n                    for activity even though both have a canonical B\n                    <jats:sub>12<\/jats:sub>\n                    -binding motif. Unanswered were what underlies this striking difference, what is the specific cobalamin used, and how it acts. Here, we show that coenzyme B\n                    <jats:sub>12<\/jats:sub>\n                    (5\u2032-deoxyadenosylcobalamin, AdoB\n                    <jats:sub>12<\/jats:sub>\n                    ), specifically dictates CarH function in the dark and on exposure to light. In the dark, AdoB\n                    <jats:sub>12<\/jats:sub>\n                    -binding to the autonomous domain containing the B\n                    <jats:sub>12<\/jats:sub>\n                    -binding motif foments repressor oligomerization, enhances operator binding, and blocks transcription. Light, at various wavelengths at which AdoB\n                    <jats:sub>12<\/jats:sub>\n                    absorbs, dismantles active repressor oligomers by photolysing the bound AdoB\n                    <jats:sub>12<\/jats:sub>\n                    and weakens repressor\u2013operator binding to allow transcription. By contrast, AdoB\n                    <jats:sub>12<\/jats:sub>\n                    alters neither CarA oligomerization nor operator binding, thus accounting for its B\n                    <jats:sub>12<\/jats:sub>\n                    -independent activity. Our findings unveil a functional facet of AdoB\n                    <jats:sub>12<\/jats:sub>\n                    whereby it serves as the chromophore of a unique photoreceptor protein class acting in light-dependent gene regulation. The prevalence of similar proteins of unknown function in microbial genomes suggests that this distinct B\n                    <jats:sub>12<\/jats:sub>\n                    -based molecular mechanism for photoregulation may be widespread in bacteria.\n                  <\/jats:p>","DOI":"10.1073\/pnas.1018972108","type":"journal-article","created":{"date-parts":[[2011,4,19]],"date-time":"2011-04-19T00:19:39Z","timestamp":1303172379000},"page":"7565-7570","update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":177,"title":["Light-dependent gene regulation by a coenzyme B\n                    <sub>12<\/sub>\n                    -based photoreceptor"],"prefix":"10.1073","volume":"108","author":[{"given":"Juan Manuel","family":"Ortiz-Guerrero","sequence":"first","affiliation":[{"name":"Department of Genetics and Microbiology, Area of Genetics (Unidad Asociada al Instituto de Qu\u00edmica F\u00edsica\u2013Consejo Superior de Investigaciones Cient\u00edficas), Faculty of Biology, Universidad de Murcia, Murcia 30100, Spain; and"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mar\u00eda Carmen","family":"Polanco","sequence":"additional","affiliation":[{"name":"Department of Genetics and Microbiology, Area of Genetics (Unidad Asociada al Instituto de Qu\u00edmica F\u00edsica\u2013Consejo Superior de Investigaciones Cient\u00edficas), Faculty of Biology, Universidad de Murcia, Murcia 30100, Spain; and"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Francisco J.","family":"Murillo","sequence":"additional","affiliation":[{"name":"Department of Genetics and Microbiology, Area of Genetics (Unidad Asociada al Instituto de Qu\u00edmica F\u00edsica\u2013Consejo Superior de Investigaciones Cient\u00edficas), Faculty of Biology, Universidad de Murcia, Murcia 30100, Spain; and"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S.","family":"Padmanabhan","sequence":"additional","affiliation":[{"name":"Instituto de Qu\u00edmica F\u00edsica \u201cRocasolano,\u201d Consejo Superior de Investigaciones Cient\u00edficas, 28006 Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Montserrat","family":"El\u00edas-Arnanz","sequence":"additional","affiliation":[{"name":"Department of Genetics and Microbiology, Area of Genetics (Unidad Asociada al Instituto de Qu\u00edmica F\u00edsica\u2013Consejo Superior de Investigaciones Cient\u00edficas), Faculty of Biology, Universidad de Murcia, Murcia 30100, Spain; and"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"341","published-online":{"date-parts":[[2011,4,18]]},"reference":[{"key":"e_1_3_3_1_2","doi-asserted-by":"publisher","DOI":"10.1038\/nature04056"},{"key":"e_1_3_3_2_2","doi-asserted-by":"publisher","DOI":"10.1146\/annurev.micro.50.1.137"},{"key":"e_1_3_3_3_2","doi-asserted-by":"publisher","DOI":"10.1038\/nature05611"},{"key":"e_1_3_3_4_2","doi-asserted-by":"publisher","DOI":"10.1039\/b108967f"},{"key":"e_1_3_3_5_2","doi-asserted-by":"publisher","DOI":"10.1186\/1471-2164-10-78"},{"key":"e_1_3_3_6_2","doi-asserted-by":"publisher","DOI":"10.1146\/annurev.biochem.66.1.269"},{"key":"e_1_3_3_7_2","doi-asserted-by":"publisher","DOI":"10.1146\/annurev.biochem.72.121801.161828"},{"key":"e_1_3_3_8_2","doi-asserted-by":"publisher","DOI":"10.1038\/nrm1403"},{"key":"e_1_3_3_9_2","doi-asserted-by":"publisher","DOI":"10.1093\/nar\/gkh167"},{"key":"e_1_3_3_10_2","doi-asserted-by":"publisher","DOI":"10.1016\/S1074-5521(02)00224-7"},{"key":"e_1_3_3_11_2","doi-asserted-by":"publisher","DOI":"10.1261\/rna.5710303"},{"key":"e_1_3_3_12_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-2958.2007.06086.x"},{"key":"e_1_3_3_13_2","first-page":"211","volume-title":"Myxobacteria: Multicellularity and Differentiation","author":"El\u00edas-Arnanz M","year":"2008","unstructured":"M El\u00edas-Arnanz, M Fontes, S Padmanabhan, Carotenogenesis in Myxococcus xanthus: A complex regulatory network. Myxobacteria: Multicellularity and Differentiation, ed DE Whitworth (ASM Press, Washington, DC), pp. 211\u2013225 (2008)."},{"key":"e_1_3_3_14_2","doi-asserted-by":"publisher","DOI":"10.1039\/b802472c"},{"key":"e_1_3_3_15_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.mib.2008.02.014"},{"key":"e_1_3_3_16_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.tim.2007.09.009"},{"key":"e_1_3_3_17_2","doi-asserted-by":"publisher","DOI":"10.1128\/jb.91.2.535-545.1966"},{"key":"e_1_3_3_18_2","doi-asserted-by":"publisher","DOI":"10.1093\/nar\/gkq277"},{"key":"e_1_3_3_19_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-2958.2006.05567.x"},{"key":"e_1_3_3_20_2","doi-asserted-by":"publisher","DOI":"10.1074\/jbc.M405225200"},{"key":"e_1_3_3_21_2","doi-asserted-by":"publisher","DOI":"10.1128\/JB.184.8.2215-2224.2002"},{"key":"e_1_3_3_22_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.7992050"},{"key":"e_1_3_3_23_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0969-2126(96)00056-1"},{"key":"e_1_3_3_24_2","first-page":"143","article-title":"Photolytic decomposition of 3 cobalamins: A quantitative study","volume":"24","author":"Bond CM","year":"1972","unstructured":"CM Bond, KA Lees, RP Enever, Photolytic decomposition of 3 cobalamins: A quantitative study. J Pharm Pharmacol 24, 143 (1972).","journal-title":"J Pharm Pharmacol"},{"key":"e_1_3_3_25_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0021-9258(19)38257-2"},{"key":"e_1_3_3_26_2","doi-asserted-by":"publisher","DOI":"10.1021\/bi700077v"},{"key":"e_1_3_3_27_2","doi-asserted-by":"publisher","DOI":"10.1074\/jbc.M403459200"},{"key":"e_1_3_3_28_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-2958.2007.05724.x"},{"key":"e_1_3_3_29_2","doi-asserted-by":"publisher","DOI":"10.1128\/JB.00736-10"},{"key":"e_1_3_3_30_2","doi-asserted-by":"publisher","DOI":"10.1074\/jbc.M703261200"},{"key":"e_1_3_3_31_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.tibs.2005.04.008"},{"key":"e_1_3_3_32_2","doi-asserted-by":"publisher","DOI":"10.1128\/JB.183.5.1577-1584.2001"},{"key":"e_1_3_3_33_2","doi-asserted-by":"publisher","DOI":"10.1007\/s00253-010-2773-2"},{"key":"e_1_3_3_34_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0076-6879(00)28390-0"},{"key":"e_1_3_3_35_2","doi-asserted-by":"publisher","DOI":"10.1021\/bi00859a040"},{"key":"e_1_3_3_36_2","doi-asserted-by":"publisher","DOI":"10.1038\/nbt956"},{"key":"e_1_3_3_37_2","doi-asserted-by":"publisher","DOI":"10.1101\/gad.603510"},{"key":"e_1_3_3_38_2","doi-asserted-by":"publisher","DOI":"10.1093\/nar\/25.17.3389"}],"container-title":["Proceedings of the National Academy of Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pnas.org\/doi\/pdf\/10.1073\/pnas.1018972108","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,4,12]],"date-time":"2022-04-12T19:37:13Z","timestamp":1649792233000},"score":1,"resource":{"primary":{"URL":"https:\/\/pnas.org\/doi\/full\/10.1073\/pnas.1018972108"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2011,4,18]]},"references-count":38,"journal-issue":{"issue":"18","published-print":{"date-parts":[[2011,5,3]]}},"alternative-id":["10.1073\/pnas.1018972108"],"URL":"https:\/\/doi.org\/10.1073\/pnas.1018972108","relation":{},"ISSN":["0027-8424","1091-6490"],"issn-type":[{"value":"0027-8424","type":"print"},{"value":"1091-6490","type":"electronic"}],"subject":[],"published":{"date-parts":[[2011,4,18]]},"assertion":[{"value":"2011-04-18","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}