Crystal structure of mammalian α1,6-fucosyltransferase, FUT8

Abstract

Mammalian alpha1,6-fucosyltransferase (FUT8) catalyses the transfer of a fucose residue from a donor substrate, guanosine 5'-diphosphate-beta-L-fucose to the reducing terminal N-acetylglucosamine (GlcNAc) of the core structure of an asparagine-linked oligosaccharide. Alpha1,6-fucosylation, also referred to as core fucosylation, plays an essential role in various pathophysiological events. Our group reported that FUT8 null mice showed severe growth retardation and emphysema-like lung-destruction as a result of the dysfunction of epidermal growth factor and transforming growth factor-beta receptors. To elucidate the molecular basis of FUT8 with respect to pathophysiology, the crystal structure of human FUT8 was determined at 2.6 A resolution. The overall structure of FUT8 was found to consist of three domains: an N-terminal coiled-coil domain, a catalytic domain, and a C-terminal SH3 domain. The catalytic region appears to be similar to GT-B glycosyltransferases rather than GT-A. The C-terminal part of the catalytic domain of FUT8 includes a Rossmann fold with three regions that are conserved in alpha1,6-, alpha1,2-, and protein O-fucosyltransferases. The SH3 domain of FUT8 is similar to other SH3 domain-containing proteins, although the significance of this domain remains to be elucidated. The present findings of FUT8 suggest that the conserved residues in the three conserved regions participate in the Rossmann fold and act as the donor binding site, or in catalysis, thus playing key roles in the fucose-transferring reaction.

Core-6 fucose and the oligomerization of the 1918 pandemic influenza viral neuraminidase

“…Core- 6 fucosylation of the reducing-end GlcNAc on N-glycans is introduced by FUT8 in humans [18]. To confirm the results of mass spectrometry analysis, the levels of core-6 fucosylation were further probed with azido fucose using recombinant human FUT8.…”

Structure of a Novel O-Linked N-Acetyl-d-glucosamine (O-GlcNAc) Transferase, GtfA, Reveals Insights into the Glycosylation of Pneumococcal Serine-rich Repeat Adhesins

“…2a). They are the N-terminal TPR domain of hOGT (PDB code 3PE4) (6) and XcOGT (PDB code 2JLB) (8), the N-terminal all ␣-domain of N-glucosyltransferase (PDB code 3Q3E) (52), the C-terminal SH3 domain of mammalian ␣-1,6-fucosyltransferase (PDB code 2DE0) (53), and the N-terminal immunoglobulin like ␤-sandwich fold domain of ␣-2,6-sialyltransferase (PDB code 2Z4T) (54). It was assumed that during evolution these add-on domains impart the defined acceptor binding specificity to glycosyltransferases (55).…”

Novel Regulation of Skp1 by the Dictyostelium AgtA α-Galactosyltransferase Involves the Skp1-binding Activity of Its WD40 Repeat Domain

“…Although the WD40 repeats of AgtA are unprecedented for known GTs, other GTs possess SH3 (14), TPR (15), and lectin (16) domains. In some instances, these so-called "add-on" domains (17) have been implicated in acceptor substrate recognition, as has the linker region of a type 2 membrane GT (18).…”