Nucleotide sugars are defined as any nucleotide in which the distal phosphoric residue of a nucleoside 5'-diphosphate is in glycosidic linkage with a monosaccharide or monosaccharide derivative. There are nine sugar nucleotides and they can be classified depending on the type of the nucleoside forming them: UDP-Glc, UDP-Gal, UDP-GlcNAc, UDP-GlcUA, UDP- Xyl, GDP-Man, GDP-Fuc and CMP-NeuNAc. Turning back now to the pathway in question, namely the nucleotide sugar metabolism pathway, it should be noted that the nucleotide sugars play an important role. Indeed, they are donors of certain important residues of sugar which are vital to glycosylation and by extension tot the production of polysaccharides. This process produces the substrates for glycosyltransferases. These sugars have several additional roles. For example, nucleotide sugars serve a vital purpose as the intermediates in interconversions of nucleotide sugars that result in the creation and activation of certain sugars necessary in the glycosylation reaction in certain organisms. Moreover, the process of glycosylation is attributed mostly (though not entirely) to the endoplasmic reticulum/golgi apparatus. Logically then, due to the important role of nucleotide sugars in glycosylation, a plethora of transporters exist which displace the sugars from their point of production, the cytoplasm, to where they are needed. In the case, the endoplasmic reticulum and golgi apparatus.

Nucleotide Sugars Metabolism References