Structures of NodZ [alpha]1,6-fucosyltransferase in complex with GDP and GDP-fucose

Journal Article · Mon Mar 26 04:00:00 EDT 2012 · Acta Crystallogr. D

DOI:https://doi.org/10.1107/S0907444911053157· OSTI ID:1034200

Brzezinski, Krzysztof; Dauter, Zbigniew; Jaskolski, Mariusz ^[1]

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1. NCI

Rhizobial NodZ {alpha}1,6-fucosyltransferase ({alpha}1,6-FucT) catalyzes the transfer of the fucose (Fuc) moiety from guanosine 5'-diphosphate-{beta}-L-fucose to the reducing end of the chitin oligosaccharide core during Nod-factor (NF) biosynthesis. NF is a key signaling molecule required for successful symbiosis with a legume host for atmospheric nitrogen fixation. To date, only two {alpha}1,6-FucT structures have been determined, both without any donor or acceptor molecule that could highlight the structural background of the catalytic mechanism. Here, the first crystal structures of {alpha}1,6-FucT in complex with its substrate GDP-Fuc and with GDP, which is a byproduct of the enzymatic reaction, are presented. The crystal of the complex with GDP-Fuc was obtained through soaking of native NodZ crystals with the ligand and its structure has been determined at 2.35 {angstrom} resolution. The fucose residue is exposed to solvent and is disordered. The enzyme-product complex crystal was obtained by cocrystallization with GDP and an acceptor molecule, penta-N-acetyl-L-glucosamine (penta-NAG). The structure has been determined at 1.98 {angstrom} resolution, showing that only the GDP molecule is present in the complex. In both structures the ligands are located in a cleft formed between the two domains of NodZ and extend towards the C-terminal domain, but their conformations differ significantly. The structures revealed that residues in three regions of the C-terminal domain, which are conserved among {alpha}1,2-, {alpha}1,6- and protein O-fucosyltransferases, are involved in interactions with the sugar-donor molecule. There is also an interaction with the side chain of Tyr45 in the N-terminal domain, which is very unusual for a GT-B-type glycosyltransferase. Only minor conformational changes of the protein backbone are observed upon ligand binding. The only exception is a movement of the loop located between strand {beta}C2 and helix {alpha}C3. In addition, there is a shift of the {alpha}C3 helix itself upon GDP-Fuc binding.

• Research Organization: Advanced Photon Source (APS), Argonne National Laboratory (ANL), Argonne, IL (US)
• Sponsoring Organization: FOREIGNNIHNCI
• OSTI ID: 1034200
• Journal Information: Acta Crystallogr. D, Journal Name: Acta Crystallogr. D Journal Issue: (2) ; 02, 2012 Vol. 68; ISSN 0907-4449
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
60 APPLIED LIFE SCIENCES
BIOSYNTHESIS
CHITIN
CONFORMATIONAL CHANGES
CRYSTAL STRUCTURE
GUANOSINE
HEXOSES
NITROGEN FIXATION
OLIGOSACCHARIDES
PROTEINS
RESIDUES
RESOLUTION
SOLVENTS
SUBSTRATES
SYMBIOSIS