GDP-α-D-glucose + phosphate = α-D-glucose 1-phosphate + GDP
GDP:α-D-glucose 1-phosphate guanylyltransferase
The enzyme may be involved in prevention of misincorporation of glucose in place of mannose residues into glycoconjugates i.e. to remove accidentally produced GDP-α-D-glucose. Activities with GDP-L-galactose, GDP-D-mannose and UDP-D-glucose are all less than 3% that with GDP-D-glucose.
Adler, L.N., Gomez, T.A., Clarke, S.G. and Linster, C.L. A novel GDP-D-glucose phosphorylase involved in quality control of the nucleoside diphosphate sugar pool in Caenorhabditis elegans and mammals. J. Biol. Chem.286 (2011) 21511–21523. [PMID: 21507950]