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Arabidopsis thaliana fucosyltransferase 1 (FUT1) in complex with GDP and a xylo-oligossacharide
Structural highlights
FunctionFUT1_ARATH Involved in cell wall biosynthesis. Is both necessary and sufficient for the addition of the terminal fucosyl residue on xyloglucan side chains, but is not involved in the fucosylation of other cell wall components (PubMed:10373113, PubMed:11743104, PubMed:11854459, PubMed:14730072). Associates with other xyloglucan-synthesizing enzymes to form multiprotein complexes for xyloglucan synthesis in the Golgi (PubMed:25392066).[1] [2] [3] [4] [5] Publication Abstract from PubMedThe plant cell wall is a complex and dynamic network made mostly of cellulose, hemicelluloses and pectins. Xyloglucan, the major hemicellulosic component in Arabidopsis thaliana, is biosynthesized in the Golgi apparatus by a series of glycan synthases and glycosyltransferases before export to the wall. A better understanding of the xyloglucan biosynthetic machinery will give clues toward engineering plants with improved wall properties or designing novel xyloglucan-based biomaterials. The xyloglucan-specific alpha-2-fucosyltransferase FUT1 catalyzes the transfer of fucose from GDP-fucose to terminal galactosyl residues on xyloglucan side chains. Here, we present crystal structures of Arabidopsis FUT1 in its apoform and in a ternary complex with GDP and a xylo-oligosaccharide acceptor (named XLLG). Although FUT1 is clearly a member of the large GT-B fold family, like other fucosyltransferases of known structures, it contains a variant of the GT-B fold. In particular, it includes an extra C-terminal region that is part of the acceptor binding site. Our crystal structures support previous findings that FUT1 behaves as a functional dimer. Mutational studies and structure comparison with other fucosyltransferases suggest that FUT1 uses a SN2-like reaction mechanism similar to that of protein-O-fucosyltransferase 2. Thus, our results provide new insights into the mechanism of xyloglucan fucosylation in the Golgi. Structure of Arabidopsis thaliana FUT1 Reveals a Variant of the GT-B Class Fold and Provides Insight into Xyloglucan Fucosylation.,Rocha J, Ciceron F, de Sanctis D, Lelimousin M, Chazalet V, Lerouxel O, Breton C Plant Cell. 2016 Sep 16. pii: tpc.00519.2016. PMID:27637560[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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