N-acetyllactosaminide beta-1,3-N-acetylglucosaminyltransferase

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In enzymology, a N-acetyllactosaminide beta-1,3-N-acetylglucosaminyltransferase (EC 2.4.1.149) is an enzyme that catalyzes the chemical reaction

UDP-N-acetyl-D-glucosamine + beta-D-galactosyl-1,4-N-acetyl-D-glucosaminyl-R $\rightleftharpoons$ UDP + N-acetyl-beta-D-glucosaminyl-1,3-beta-D-galactosyl-1,4-N-acetyl-D- glucosaminyl-R

Thus, the two substrates of this enzyme are UDP-N-acetyl-D-glucosamine and beta-D-galactosyl-1,4-N-acetyl-D-glucosaminyl-R, whereas its 3 products are UDP, N-acetyl-beta-D-glucosaminyl-1,3-beta-D-galactosyl-1,4-N-acetyl-D-, and glucosaminyl-R.

This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP-N-acetyl-D-glucosamine:beta-D-galactosyl-1,4-N-acetyl-D-glucosam ine beta-1,3-acetyl-D-glucosaminyltransferase. Other names in common use include uridine diphosphoacetylglucosamine-acetyllactosaminide, beta1->3-acetylglucosaminyltransferase, poly-N-acetyllactosamine extension enzyme, Galbeta1->4GlcNAc-R beta1->3 N-acetylglucosaminyltransferase, UDP-GlcNAc:GalR, beta-D-3-N-acetylglucosaminyltransferase, N-acetyllactosamine beta(1-3)N-acetylglucosaminyltransferase, UDP-GlcNAc:Galbeta1->4GlcNAcbeta-Rbeta1->3-N-, acetylglucosaminyltransferase, and GnTE. This enzyme participates in 4 metabolic pathways: keratan sulfate biosynthesis, glycosphingolipid biosynthesis - neo-lactoseries, glycan structures - biosynthesis 1, and glycan structures - biosynthesis 2.

[edit] References

IUBMB entry for 2.4.1.149
BRENDA references for 2.4.1.149 (Recommended.)
PubMed references for 2.4.1.149
PubMed Central references for 2.4.1.149
Google Scholar references for 2.4.1.149
Takeya A, Hosomi O, Kogure T (1985). "The presence of N-acetyllactosamine and lactose: beta (1-3)N-acetylglucosaminyltransferase activity in human urine". Jpn. J. Med. Sci. Biol. 38: 1–8. PMID 3160874.
van den Eijnden DH, Winterwerp H, Smeeman P, Schiphorst WE (1983). "Novikoff ascites tumor cells contain N-acetyllactosaminide beta 1 leads to 3 and beta 1 leads to 6 N-acetylglucosaminyltransferase activity". J. Biol. Chem. 258: 3435–7. PMID 6219989.