169906 20260306154908.0 doi 10.1038/s41467-026-68786-6 sideral 148443 ART-2026-148443 eng Taleb, Víctor (orcid)0000-0001-9224-5854 Plant fucosyltransferase FUT11 distorts the sugar acceptor to catalyze via a transient oxocarbenium intermediate mechanism 2026 Glycosyltransferases catalyze glycosidic bond formation by activating the donor sugar, while the sugar acceptor substrate is considered passive, maintaining a chair conformation during catalysis. We challenge this through a multidisciplinary study of Arabidopsis thaliana FUT11, a core α1,3-fucosyltransferase essential for plant development and reproduction. AtFUT11 adopts a GT-B fold with an additional N-terminal subdomain that anchors the G0 N-glycan, while the α1,3 arm is mainly recognized by the acceptor Rossmann subdomain. The α1,6 arm remains solvent-exposed, allowing diverse modifications, while solvent exposure of the central mannose’s OH2 explains tolerance for β1,2-xylose. Remarkably, simulations suggest the catalytic base Glu158 may promote the innermost GlcNAc’s transient puckering distortion to align the hydroxyl for nucleophilic attack. This enables an asynchronous SN2-like mechanism bordering SN1 character, with formation of a transient oxocarbenium ion triggered by pyrophosphate departure, followed by nucleophilic attack coupled with proton transfer. Homology with human FUT9 explains AtFUT11’s side activity on LacNAc, revealing plasticity and evolutionary convergence between plant and mammalian antenna-fucosyltransferases. Access copy available to the general public Unrestricted info:eu-repo/grantAgreement/ES/DGA-FEDER/E34-R17 info:eu-repo/grantAgreement/ES/DGA/LMP58_18 info:eu-repo/grantAgreement/ES/MICINN AEI/PID2022-136362NB-I00 info:eu-repo/grantAgreement/ES/MICINN/PID2022-137973NB-I00 info:eu-repo/semantics/openAccess by-nc-nd https://creativecommons.org/licenses/by-nc-nd/4.0/deed.es info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Sanz-Martínez, Ignacio Serna, Sonia Bort-Griñó, María Narimatsu, Yoshiki Furukawa, Sanae Reichardt, Niels C. Clausen, Henrik Merino, Pedro Universidad de Zaragoza (orcid)0000-0002-2202-3460 Hurtado-Guerrero, Ramon (orcid)0000-0002-3122-9401 2013 765 Universidad de Zaragoza Dpto. Química Orgánica Área Química Orgánica 17 (2026), 1960 [18 pp.] Nature communications 2041-1723 3351047 http://zaguan.unizar.es/record/169906/files/texto_completo.pdf Versión publicada 2542500 http://zaguan.unizar.es/record/169906/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:169906 articulos driver 2026-03-06-14:50:13 ARTICLE