Phosphomannomutase 1 (PMM1)

Phosphomannomutase 1 is an enzyme encoded by the PMM1 gene.Phosphomannomutase catalyzes the conversion between D-mannose 6-phosphate and D-mannose 1-phosphate which is a substrate for GDP-mannose synthesis. GDP-mannose is used for synthesis of dolichol-phosphate-mannose, which is essential for N-linked glycosylation and thus the secretion of several glycoproteins as well as for the synthesis of glycosyl-phosphatidyl-inositol (GPI) anchored proteins.

The deduced 262-amino acid protein has a predicted molecular mass of 29 kD and shares 54% sequence identity with yeast phosphomannomutase. Expression of the human cDNA in Escherichia coli yielded an active phosphomannomutase that was purified to homogeneity.