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Due to the limited diameters of passive diffusion channels, bulky molecules such as iron\u2013siderophores and complex oligosaccharides are assumed to be taken up exclusively by active transporters. Here we assert that this assumption is incorrect. Using a combination of biophysical and computational approaches, we show that the OM protein CymA (cyclodextrin metabolism A) from\n                    <jats:italic>Klebsiella oxytoca<\/jats:italic>\n                    represents a previously unidentified paradigm in OM transport by mediating the passive diffusion of cyclic oligosaccharides (cyclodextrins) with diameters of \u223c15 \u00c5.\n                  <\/jats:p>","DOI":"10.1073\/pnas.1424835112","type":"journal-article","created":{"date-parts":[[2015,5,27]],"date-time":"2015-05-27T10:35:29Z","timestamp":1432722929000},"update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":75,"title":["Outer-membrane translocation of bulky small molecules by passive diffusion"],"prefix":"10.1073","volume":"112","author":[{"given":"Bert","family":"van den Berg","sequence":"first","affiliation":[{"name":"Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, United Kingdom;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Satya","family":"Prathyusha Bhamidimarri","sequence":"additional","affiliation":[{"name":"School of Engineering and Science, Jacobs University Bremen, 28759 Bremen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jigneshkumar","family":"Dahyabhai Prajapati","sequence":"additional","affiliation":[{"name":"School of Engineering and Science, Jacobs University Bremen, 28759 Bremen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ulrich","family":"Kleinekath\u00f6fer","sequence":"additional","affiliation":[{"name":"School of Engineering and Science, Jacobs University Bremen, 28759 Bremen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mathias","family":"Winterhalter","sequence":"additional","affiliation":[{"name":"School of Engineering and Science, Jacobs University Bremen, 28759 Bremen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"341","published-online":{"date-parts":[[2015,5,26]]},"reference":[{"key":"e_1_3_4_1_2","doi-asserted-by":"crossref","first-page":"593","DOI":"10.1128\/MMBR.67.4.593-656.2003","article-title":"Molecular basis of bacterial outer membrane permeability revisited","volume":"67","author":"Nikaido H","year":"2003","unstructured":"H Nikaido, Molecular basis of bacterial outer membrane permeability revisited. 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