Fuc12Gal

Fuc12Gal is a hypothetical glycosyltransferase used in glycoscience education and computational modeling to illustrate enzymes that assemble fucose-containing glycans. The name suggests a linkage between a fucose residue and a galactose unit, forming a fucosylated galactose motif. It is not associated with a verified protein sequence or organism, and there is no experimental characterization in peer-reviewed literature.

Proposed function and mechanism: In silico models assign Fuc12Gal the role of transferring a fucose donor to a galactose acceptor, thereby generating a fucosylated galactose linkage. The reaction type and donor/acceptor specificities are inferred from analogies to known fucosyltransferases and galactosyltransferases; exact substrates, linkage position, and donor molecules vary across simulations. The concept is used to discuss how glycosylation steps might be arranged in a biosynthetic pathway.

Structure and family: Fuc12Gal is typically depicted as belonging to the GT-B fold glycosyltransferases, featuring two Rossmann-like domains. In educational models, active-site residues and catalytic geometry are hypothetical and not supported by experimental data. Predicted requirements—such as a divalent cation for catalysis and a potential inverting or retaining mechanism—are illustrative and model-dependent.

Biological context and use in education: In teaching materials and synthetic biology demonstrations, Fuc12Gal serves as a minimal example of a two-domain glycosyltransferase and helps illustrate concepts of enzyme annotation, substrate specificity, and glycan diversification. It is not presented as a confirmed native enzyme or as a target in experimental systems.

See also: Glycosyltransferase, Fucosylation, Galactose, GT-B fold.