Mannose-1-phosphate guanyltransferase beta is an enzyme that in humans is encoded by the GMPPBgene.[4]
This gene is thought to encode a GDP-mannose pyrophosphorylase. This enzyme catalyzes the reaction which converts mannose-1-phosphate and GTP to GDP-mannose which is involved in the production of N-linked oligosaccharides. The gene encodes two transcript variants.[4]
Ning B, Elbein AD (2001). "Cloning, expression and characterization of the pig liver GDP-mannose pyrophosphorylase. Evidence that GDP-mannose and GDP-Glc pyrophosphorylases are different proteins". Eur. J. Biochem. 267 (23): 6866–74. doi:10.1046/j.1432-1033.2000.01781.x. PMID11082198.