GDP-M1P_Guanylyltransferase catalyzes the formation of GDP-Mannose.
GDP-mannose-1-phosphate guanylyltransferase, also called GDP-mannose pyrophosphorylase (GDP-MP), catalyzes the formation of GDP-Mannose from mannose-1-phosphate and GTP. Mannose is a key monosaccharide for glycosylation of proteins and lipids. GDP-Mannose is the activated donor for mannosylation of various biomolecules. This enzyme is known to be bifunctional, as both mannose-6-phosphate isomerase and mannose-1-phosphate guanylyltransferase. This CD covers the N-terminal GDP-mannose-1-phosphate guanylyltransferase domain, whereas the isomerase function is located at the C-terminal half. GDP-MP is a member of the nucleotidyltransferase family of enzymes.