In enzymology, a mannose-1-phosphate guanylyltransferase (EC 2.7.7.13) is an enzyme that catalyzes the chemical reaction Thus, the two substrates of this enzyme are GTP and alpha-D-mannose 1-phosphate, whereas its two products are diphosphate and GDP-mannose.
This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing nucleotide groups (nucleotidyltransferases).
The systematic name of this enzyme class is GTP:alpha-D-mannose-1-phosphate guanylyltransferase.
This enzyme participates in fructose and mannose metabolism.
As of late 2007, only one structure has been solved for this class of enzymes, with the PDB accession code 2CU2.