IUBMB Enzyme Nomenclature


Accepted name: glutamine—fructose-6-phosphate transaminase (isomerizing)

Reaction: L-glutamine + D-fructose 6-phosphate = L-glutamate + D-glucosamine 6-phosphate

For diagram click here.

Other names: hexosephosphate aminotransferase; glucosamine-6-phosphate isomerase (glutamine-forming); glutamine-fructose-6-phosphate transaminase (isomerizing); D-fructose-6-phosphate amidotransferase; glucosaminephosphate isomerase; glucosamine 6-phosphate synthase; GlcN6P synthase

Systematic name: L-glutamine:D-fructose-6-phosphate isomerase (deaminating)

Comments: Although the overall reaction is that of a transferase, the mechanism involves the formation of ketimine between fructose 6-phosphate and a 6-amino group from a lysine residue at the active site, which is subsequently displaced by ammonia (transamidination). Formerly EC

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9030-45-9


1. Ghosh, S., Blumenthal, H.J., Davidson, E. and Roseman, S. Glucosamine metabolism. V. Enzymatic synthesis of glucosamine 6-phosphate. J. Biol. Chem. 235 (1960) 1265-1273.

2. Gryder, R.M. and Pogell, B.M. Further studies on glucosamine 6-phosphate synthesis by rat liver enzymes. J. Biol. Chem. 235 (1960) 558-562.

3. Leloir, L.F. and Cardini, C.E. The biosynthesis of glucosamine. Biochim. Biophys. Acta 12 (1953) 15-22.

4. Teplyakov, A., Obmolova, G., Badet-Denisot, M.A. and Badet, B. The mechanism of sugar phosphate isomerization by glucosamine 6-phosphate synthase. Protein Sci. 8 (1999) 596-602. [PMID: 10091662]

[EC created 1961, deleted 1972, reinstated 1984, modified 2000 (EC created 1972, incorporated 1984)]

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