Accepted name: glucosamine-phosphate N-acetyltransferase
Reaction: acetyl-CoA + D-glucosamine 6-phosphate = CoA + N-acetyl-D-glucosamine 6-phosphate
Other name(s): phosphoglucosamine transacetylase; phosphoglucosamine acetylase; glucosamine-6-phosphate acetylase; D-glucosamine-6-P N-acetyltransferase; aminodeoxyglucosephosphate acetyltransferase; glucosamine 6-phosphate acetylase; glucosamine 6-phosphate N-acetyltransferase; N-acetylglucosamine-6-phosphate synthase; phosphoglucosamine N-acetylase; glucosamine-6-phosphate N-acetyltransferase
Systematic name: acetyl-CoA:D-glucosamine-6-phosphate N-acetyltransferase
1.  Davidson, E.A. Glucosamine 6-phosphate N-acetylase. Methods Enzymol. 9 (1966) 704–707.
2.  Davidson, E.A., Blumenthal, H.J. and Roseman, F. Glucosamine metabolism. II. Studies of glucosamine 6-phosphate N-acetylase. J. Biol. Chem. 226 (1957) 125–133. [PMID: 13428743]
3.  Pattabiraman, T.N. and Bachhawat, B.K. Purification of glucosamine-6-phosphate N-acetylase from sheep brain. Biochim. Biophys. Acta 59 (1962) 681–689. [PMID: 14484387]
4.  Boehmelt, G., Fialka, I., Brothers, G., McGinley, M.D., Patterson, S.D., Mo, R., Hui, C.C., Chung, S., Huber, L.A., Mak, T.W. and Iscove, N.N. Cloning and characterization of the murine glucosamine-6-phosphate acetyltransferase EMeg32. Differential expression and intracellular membrane association. J. Biol. Chem. 275 (2000) 12821–12832. [PMID: 10777580]
[EC created 1961, modified 2002]
Accepted name: glutamine—fructose-6-phosphate transaminase (isomerizing)
Reaction: L-glutamine + D-fructose 6-phosphate = L-glutamate + D-glucosamine 6-phosphate
Other name(s): 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).
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. [PMID: 13827775]
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. [PMID: 13829889]
3.  Leloir, L.F. and Cardini, C.E. The biosynthesis of glucosamine. Biochim. Biophys. Acta 12 (1953) 15–22. [PMID: 13115409]
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)]
Accepted name: glucosamine kinase
Reaction: ATP + D-glucosamine = ADP + D-glucosamine 6-phosphate
Glossary: D-glucosamine 6-phosphate = 2-amino-2-deoxy-D-glucose 6-phosphate
Other name(s): glucosamine kinase (phosphorylating); ATP:2-amino-2-deoxy-D-glucose-6-phosphotransferase; aminodeoxyglucose kinase; ATP:D-glucosamine phosphotransferase
Systematic name: ATP:D-glucosamine 6-phosphotransferase
Comments: The enzyme is specific for glucosamine and has only a minor activity with D-glucose. Two unrelated enzymes with this activity have been described. One type was studied in the bacterium Vibrio cholerae, where it participates in a chitin degradation pathway. The other type has been described from actinobacteria, where it is involved in the incorporation of environmental glucosamine into antibiotic biosynthesis pathways. cf. EC, ADP-specific glucose/glucosamine kinase.
1.  Bueding, E. and MacKinnon, J.A. Hexokinases of Schistosoma mansoni. J. Biol. Chem. 215 (1955) 495–506. [PMID: 13242546]
2.  Park, J.K., Wang, L.X. and Roseman, S. Isolation of a glucosamine-specific kinase, a unique enzyme of Vibrio cholerae. J. Biol. Chem. 277 (2002) 15573–15578. [PMID: 11850417]
3.  Manso, J.A., Nunes-Costa, D., Macedo-Ribeiro, S., Empadinhas, N. and Pereira, P.J.B. Molecular fingerprints for a novel enzyme family in actinobacteria with glucosamine kinase activity. MBio 10:e00239-19 (2019). [PMID: 31088917]
[EC created 1961, modified 2014, modified 2020]
Accepted name: N-acetylglucosamine kinase
Reaction: ATP + N-acetyl-D-glucosamine = ADP + N-acetyl-D-glucosamine 6-phosphate
Other name(s): acetylglucosamine kinase (phosphorylating); ATP:2-acetylamino-2-deoxy-D-glucose 6-phosphotransferase; 2-acetylamino-2-deoxy-D-glucose kinase; acetylaminodeoxyglucokinase
Systematic name: ATP:N-acetyl-D-glucosamine 6-phosphotransferase
Comments: The bacterial enzyme also acts on D-glucose.
1.  Asensio, C. and Ruiz-Amil, M. N-Acetyl-D-glucosamine kinase. II. Escherichia coli. Methods Enzymol. 9 (1966) 421–425.
2.  Barkulis, S.S. N-Acetyl-D-glucosamine kinase. I. Streptococcus pyrogenes. Methods Enzymol. 9 (1966) 415–420.
3.  Datta, A. Studies on hog spleen N-acetylglucosamine kinase. I. Purification and properties of N-acetylglucosamine kinase. Biochim. Biophys. Acta 220 (1970) 51–60. [PMID: 4319609]
[EC created 1972]
Accepted name: ADP-specific glucose/glucosamine kinase
Reaction: (1) ADP + D-glucose = AMP + D-glucose 6-phosphate
(2) ADP + D-glucosamine = AMP + D-glucosamine 6-phosphate
Other name(s): ADP-specific glucokinase; ADP-dependent glucokinase
Systematic name: ADP:D-glucose/D-glucosamine 6-phosphotransferase
Comments: Requires Mg2+. The enzyme, characterized from a number of hyperthermophilic archaeal species, is highly specific for ADP. No activity is detected when ADP is replaced by ATP, GDP, phosphoenolpyruvate, diphosphate or polyphosphate.
1.  Kengen, S.W., Tuininga, J.E., de Bok, F.A., Stams, A.J. and de Vos, W.M. Purification and characterization of a novel ADP-dependent glucokinase from the hyperthermophilic archaeon Pyrococcus furiosus. J. Biol. Chem. 270 (1995) 30453–30457. [PMID: 8530474]
2.  Koga, S., Yoshioka, I., Sakuraba, H., Takahashi, M., Sakasegawa, S., Shimizu, S. and Ohshima, T. Biochemical characterization, cloning, and sequencing of ADP-dependent (AMP-forming) glucokinase from two hyperthermophilic archaea, Pyrococcus furiosus and Thermococcus litoralis. J. Biochem. 128 (2000) 1079–1085. [PMID: 11098152]
3.  Aslam, M., Takahashi, N., Matsubara, K., Imanaka, T., Kanai, T. and Atomi, H. Identification of the glucosamine kinase in the chitinolytic pathway of Thermococcus kodakarensis. J. Biosci. Bioeng. 125:S1389-1723( (2018). [PMID: 29146530]
[EC created 2001, modified 2020]
Accepted name: protein-Nπ-phosphohistidine—N-acetyl-D-glucosamine phosphotransferase
Reaction: [protein]-Nπ-phospho-L-histidine + N-acetyl-D-glucosamine[side 1] = [protein]-L-histidine + N-acetyl-D-glucosamine 6-phosphate[side 2]
Other name(s): nagE (gene name); N-acetyl-D-glucosamine PTS permease; EIINag; Enzyme IINag; EIICBANag
Systematic name: protein-Nπ-phospho-L-histidine:N-acetyl-D-glucosamine Nπ-phosphotransferase
Comments: This enzyme is a component (known as enzyme II) of a phosphoenolpyruvate (PEP)-dependent, sugar transporting phosphotransferase system (PTS). The system, which is found only in prokaryotes, simultaneously transports its substrate from the periplasm or extracellular space into the cytoplasm and phosphorylates it. The phosphate donor, which is shared among the different systems, is a phospho-carrier protein of low molecular mass that has been phosphorylated by EC (phosphoenolpyruvate—protein phosphotransferase). Enzyme II, on the other hand, is specific for a particular substrate, although in some cases alternative substrates can be transported with lower efficiency. The reaction involves a successive transfer of the phosphate group to several amino acids within the enzyme before the final transfer to the substrate.
1.  White, R.J. The role of the phosphoenolpyruvate phosphotransferase system in the transport of N-acetyl-D-glucosamine by Escherichia coli. Biochem. J. 118 (1970) 89–92. [PMID: 4919472]
2.  Rogers, M.J., Ohgi, T., Plumbridge, J. and Soll, D. Nucleotide sequences of the Escherichia coli nagE and nagB genes: the structural genes for the N-acetylglucosamine transport protein of the bacterial phosphoenolpyruvate: sugar phosphotransferase system and for glucosamine-6-phosphate deaminase. Gene 62 (1988) 197–207. [PMID: 3284790]
3.  Peri, K.G. and Waygood, E.B. Sequence of cloned enzyme IIN-acetylglucosamine of the phosphoenolpyruvate:N-acetylglucosamine phosphotransferase system of Escherichia coli. Biochemistry 27 (1988) 6054–6061. [PMID: 3056518]
4.  Plumbridge, J. An alternative route for recycling of N-acetylglucosamine from peptidoglycan involves the N-acetylglucosamine phosphotransferase system in Escherichia coli. J. Bacteriol. 191 (2009) 5641–5647. [PMID: 19617367]
[EC created 1972 as EC, part transferred 2016 to EC]
Accepted name: N-acetylglucosamine-6-phosphate deacetylase
Reaction: N-acetyl-D-glucosamine 6-phosphate + H2O = D-glucosamine 6-phosphate + acetate
Other name(s): acetylglucosamine phosphate deacetylase; acetylaminodeoxyglucosephosphate acetylhydrolase; 2-acetamido-2-deoxy-D-glucose-6-phosphate amidohydrolase
Systematic name: N-acetyl-D-glucosamine-6-phosphate amidohydrolase
1.  White, R.J. and Pasternak, C.A. The purification and properties of N-acetylglucosamine 6-phosphate deacetylase from Escherichia coli. Biochem. J. 105 (1967) 121–125. [PMID: 4861885]
2.  Yamano, N., Matsushita, Y., Kamada, Y., Fujishima, S., Arita, M. Purification and characterization of N-acetylglucosamine 6-phosphate deacetylase with activity against N-acetylglucosamine from Vibrio cholerae non-O1. Biosci. Biotechnol. Biochem. 60 (1996) 1320–1323. [PMID: 8987551]
[EC created 1972 (EC created 1999, incorporated 2002)]
Accepted name: glucosamine-6-phosphate deaminase
Reaction: α-D-glucosamine 6-phosphate + H2O = D-fructose 6-phosphate + NH3
Glossary: α-D-glucosamine 6-phosphate = 2-amino-2-deoxy-α-D-glucopyranose 6-phosphate
Other name(s): glucosaminephosphate isomerase (ambiguous); glucosamine-6-phosphate isomerase (ambiguous); phosphoglucosaminisomerase (ambiguous); glucosamine phosphate deaminase; aminodeoxyglucosephosphate isomerase (ambiguous); phosphoglucosamine isomerase (ambiguous); 2-amino-2-deoxy-D-glucose-6-phosphate aminohydrolase (ketol isomerizing)
Systematic name: 2-amino-2-deoxy-α-D-glucose-6-phosphate aminohydrolase (ketol isomerizing)
Comments: The enzyme uses ring opening and isomerization of the aldose-ketose type to convert the -CH(-NH2)-CH=O group of glucosamine 6-phosphate into -C(=NH)-CH2-OH, forming 2-deoxy-2-imino-D-arabino-hexitol, which then hydrolyses to yield fructose 6-phosphate and ammonia. N-Acetyl-D-glucosamine 6-phosphate, which is not broken down, activates the enzyme.
1.  Wolfe, J.B., Britton, B.B., Nakada, H.I. Glucosamine degradation by Escherichia coli. III. Isolation and studies of "phosphoglucosaminisomerase". Arch. Biochem. Biophys. 66 (1957) 333–339. [PMID: 13403679]
2.  Comb, D.G., Roseman, S. Glucosamine metabolism. IV. Glucosamine-6-phosphate deaminase. J. Biol. Chem. 232 (1958) 807–827. [PMID: 13549465]
3.  Pattabiraman, T.N., Bachhawat, B.K. Purification of glucosamine 6-phosphate deaminase from human brain. Biochim. Biophys. Acta 54 (1961) 273–283. [PMID: 14484386]
4.  Liu, C., Li, D., Liang, Y.H., Li, L.F. and Su, X.D. Ring-opening mechanism revealed by crystal structures of NagB and its ES intermediate complex. J. Mol. Biol. 379 (2008) 73–81. [PMID: 18436239]
[EC created 1961 as EC, transferred 2000 to EC]
Accepted name: N-acetylmuramic acid 6-phosphate etherase
Reaction: (R)-lactate + N-acetyl-D-glucosamine 6-phosphate = N-acetylmuramate 6-phosphate + H2O
Other name(s): MurNAc-6-P etherase; MurQ
Systematic name: (R)-lactate hydro-lyase (adding N-acetyl-D-glucosamine 6-phosphate; N-acetylmuramate 6-phosphate-forming)
Comments: This enzyme, along with EC, anhydro-N-acetylmuramic acid kinase, is required for the utilization of anhydro-N-acetylmuramic acid in proteobacteria. The substrate is either imported from the medium or derived from the bacterium’s own cell wall murein during cell wall recycling.
1.  Jaeger, T., Arsic, M. and Mayer, C. Scission of the lactyl ether bond of N-acetylmuramic acid by Escherichia coli "etherase". J. Biol. Chem. 280 (2005) 30100–30106. [PMID: 15983044]
2.  Uehara, T., Suefuji, K., Valbuena, N., Meehan, B., Donegan, M. and Park, J.T. Recycling of the anhydro-N-acetylmuramic acid derived from cell wall murein involves a two-step conversion to N-acetylglucosamine-phosphate. J. Bacteriol. 187 (2005) 3643–3649. [PMID: 15901686]
3.  Uehara, T., Suefuji, K., Jaeger, T., Mayer, C. and Park, J.T. MurQ etherase is required by Escherichia coli in order to metabolize anhydro-N-acetylmuramic acid obtained either from the environment or from its own cell wall. J. Bacteriol. 188 (2006) 1660–1662. [PMID: 16452451]
4.  Hadi, T., Dahl, U., Mayer, C. and Tanner, M.E. Mechanistic studies on N-acetylmuramic acid 6-phosphate hydrolase (MurQ): an etherase involved in peptidoglycan recycling. Biochemistry 47 (2008) 11547–11558. [PMID: 18837509]
5.  Jaeger, T. and Mayer, C. N-acetylmuramic acid 6-phosphate lyases (MurNAc etherases): role in cell wall metabolism, distribution, structure, and mechanism. Cell. Mol. Life Sci. 65 (2008) 928–939. [PMID: 18049859]
[EC created 2011]
Accepted name: N-acylglucosamine-6-phosphate 2-epimerase
Reaction: N-acyl-D-glucosamine 6-phosphate = N-acyl-D-mannosamine 6-phosphate
Other name(s): acylglucosamine-6-phosphate 2-epimerase; acylglucosamine phosphate 2-epimerase
Systematic name: N-acyl-D-glucosamine-6-phosphate 2-epimerase
1.  Ghosh, S. and Roseman, S. The sialic acids. IV. N-Acyl-D-glucosamine 6-phosphate 2-epimerase. J. Biol. Chem. 240 (1965) 1525–1530. [PMID: 14285487]
[EC created 1972]
Accepted name: D-glucosamine-6-phosphate 4-epimerase
Reaction: D-glucosamine 6-phosphate = D-galactosamine 6-phosphate
Other name(s): ST2245 (locus name)
Systematic name: D-glucosamine 6-phosphate 4-epimerase
Comments: The enzyme, characterized from the archaeon Sulfolobus tokodaii, participates in a pathway for the biosynthesis of UDP-N-acetyl-α-D-galactosamine.
1.  Dadashipour, M., Iwamoto, M., Hossain, M.M., Akutsu, J.I., Zhang, Z. and Kawarabayasi, Y. Identification of a direct biosynthetic pathway for UDP-N-acetylgalactosamine from glucosamine-6-phosphate in thermophilic crenarchaeon Sulfolobus tokodaii. J. Bacteriol. 200 (2018) . [PMID: 29507091]
[EC created 2018]
Accepted name: phosphoacetylglucosamine mutase
Reaction: N-acetyl-α-D-glucosamine 1-phosphate = N-acetyl-D-glucosamine 6-phosphate
Other name(s): acetylglucosamine phosphomutase; acetylglucosamine phosphomutase; acetylaminodeoxyglucose phosphomutase; phospho-N-acetylglucosamine mutase; N-acetyl-D-glucosamine 1,6-phosphomutase
Systematic name: N-acetyl-α-D-glucosamine 1,6-phosphomutase
Comments: The enzyme is activated by N-acetyl-α-D-glucosamine 1,6-bisphosphate.
1.  Carlson, D.M. Phosphoacetylglucosamine mutase from pig submaxillary gland. Methods Enzymol. 8 (1966) 179–182.
2.  Leloir, L.F. and Cardini, C.E. Enzymes acting on glucosamine phosphates. Biochim. Biophys. Acta 20 (1956) 33–42. [PMID: 13315346]
3.  Ray, W.J., Jr. and Peck, E.J., Jr. Phosphomutases. In: Boyer, P.D. (Ed.), The Enzymes, 3rd edn, vol. 6, 1972, pp. 407–477.
4.  Reissig, J.L. and Leloir, L.F. Phosphoacetylglucosamine mutase from Neurospora. Methods Enzymol. 8 (1966) 175–178.
[EC created 1961 as EC, transferred 1984 to EC]
Accepted name: phosphoglucosamine mutase
Reaction: α-D-glucosamine 1-phosphate = D-glucosamine 6-phosphate
Systematic name: α-D-glucosamine 1,6-phosphomutase
Comments: The enzyme is involved in the pathway for bacterial cell-wall peptidoglycan and lipopolysaccharide biosyntheses, being an essential step in the pathway for UDP-N-acetylglucosamine biosynthesis. The enzyme from Escherichia coli is activated by phosphorylation and can be autophosphorylated in vitro by α-D-glucosamine 1,6-bisphosphate, which is an intermediate in the reaction, α-D-glucose 1,6-bisphosphate or ATP. It can also catalyse the interconversion of α-D-glucose 1-phosphate and glucose 6-phosphate, although at a much lower rate.
1.  Mengin-Lecreulx, D. and van Heijenoort, J. Characterization of the essential gene glmM encoding phosphoglucosamine mutase in Escherichia coli. J. Biol. Chem. 271 (1996) 32–39. [PMID: 8550580]
2.  de Reuse, H., Labigne, A. and Mengin-Lecreulx, D. The Helicobacter pylori ureC gene codes for a phosphoglucosamine mutase. J. Bacteriol. 179 (1997) 3488–3493. [PMID: 9171391]
3.  Jolly, L., Wu, S., van Heijenoort, J., de Lencastre, H., Mengin-Lecreulx, D. and Tomas, A. The femR315 gene from Staphylococcus aureus, the interruption of which results in reduced methicillin resistance, encodes a phosphoglucosamine mutase. J. Bacteriol. 179 (1997) 5321–5325. [PMID: 9286983]
4.  Jolly, L., Ferrari, P., Blanot, D., van Heijenoort, J., Fassy, F. and Mengin-Lecreulx, D. Reaction mechanism of phosphoglucosamine mutase from Escherichia coli. Eur. J. Biochem. 262 (1999) 202–210. [PMID: 10231382]
5.  Jolly, L., Pompeo, F., van Heijenoort, J., Fassy, F. and Mengin-Lecreulx, D. Autophosphorylation of phosphoglucosamine mutase from Escherichia coli. J. Bacteriol. 182 (2000) 1280–1285. [PMID: 10671448]
[EC created 2001]
Accepted name: phosphogalactosamine mutase
Reaction: D-galactosamine 6-phosphate = α-D-galactosamine-1-phosphate
Other name(s): ST0242 (locus name)
Systematic name: α-D-galactosamine 1,6-phosphomutase
Comments: The enzyme, characterized from the archaeon Sulfolobus tokodaii, is also active toward D-glucosamine 6-phosphate (cf. EC, phosphoglucosamine mutase).
1.  Dadashipour, M., Iwamoto, M., Hossain, M.M., Akutsu, J.I., Zhang, Z. and Kawarabayasi, Y. Identification of a direct biosynthetic pathway for UDP-N-acetylgalactosamine from glucosamine-6-phosphate in thermophilic crenarchaeon Sulfolobus tokodaii. J. Bacteriol. 200 (2018) . [PMID: 29507091]
[EC created 2018]