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 5.3.1.19.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9030-45-9
References:
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]