Mannose and fructose metabolism

The mannose and fructose metabolism pathway presented here is same as the MPMP pathway of same name (http://sites.huji.ac.il/malaria/maps/mannosemetpath.html). The genes for all the enzymes in this pathway are identified in Toxoplasma gondii genome. This pathway utilises fructose, a hexose (may be from host) and fructose-6-phosphate, a glycolysis intermediate for the production of important nucleotide sugars such as GDP-D-mannose and GDP-L-fucose. These compounds are essential substrates for glycosylphosphatidylinositol (GPI) anchor biosynthesis and synthesis of the anchors for N-glycans (N-glycans biosynthesis). 

 

Enzyme EC Number Gene id Protein localisation Localisation data source
GDP-L-fucose synthase 1.1.1.271 TGME49_286220 Nucleus Previous publication
Hexokinase 2.7.1.1 TGME49_265450 Cytosol Apiloc; Previous publication
Mannose-1-phosphate guanylyltransferase 2.7.7.13 TGME49_257960 Mitochondrion Previous publication
GDP-mannose 4,6-dehydratase 4.2.1.47 TGME49_238940 Nucleus Previous publication
Mannose-6-phosphate isomerase 5.3.1.8 TGME49_260140    
Phosphomannomutase 5.4.2.8 TGME49_239710 Cytosol; Cytoskeleton GO annotation; Previous publication

 

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Sources and fates of metabolites

 

Substrate Source pathways Product Fate pathways
beta-D-Fructose-6P Glycolysis GDP-D-Mannose N-glycan biosynthesis
beta-D-Fructose Starch and galactose metabolism, Host GDP-L-Fucose N-glycan biosynthesis
D-Mannose Host