In enzymology, a beta-galactoside alpha-2,3-sialyltransferase (EC 2.4.99.4) is an enzyme that catalyzes the chemical reaction
| beta-galactoside alpha-2,3-sialyltransferase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 2.4.99.4 | ||||||||
| CAS no. | 71124-51-1 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| Gene Ontology | AmiGO / QuickGO | ||||||||
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- CMP-N-acetylneuraminate + beta-D-galactosyl-1,3-N-acetyl-alpha-D-galactosaminyl-R CMP + alpha-N-acetylneuraminyl-2,3-beta-D-galactosyl-1,3-N-acetyl-alpha-D- galactosaminyl-R
Thus, the two substrates of this enzyme are CMP-N-acetylneuraminate and beta-D-galactosyl-1,3-N-acetyl-alpha-D-galactosaminyl-R, whereas its 3 products are CMP, alpha-N-acetylneuraminyl-2,3-beta-D-galactosyl-1,3-N-acetyl-alpha-D-, and galactosaminyl-R.
This enzyme belongs to the family of transferases, specifically those glycosyltransferases that do not transfer hexosyl or pentosyl groups. The systematic name of this enzyme class is CMP-N-acetylneuraminate:beta-D-galactoside alpha-2,3-N-acetylneuraminyl-transferase. This enzyme participates in 7 metabolic pathways: O-glycan biosynthesis, keratan sulfate biosynthesis, glycosphingolipid biosynthesis - lactoseries, glycosphingolipid biosynthesis - globoseries, glycosphingolipid biosynthesis - ganglioseries, glycan structures - biosynthesis 1, and glycan structures - biosynthesis 2.
Structural studies
editAs of late 2007, 9 structures have been solved for this class of enzymes, with PDB accession codes 2EX0, 2EX1, 2IHJ, 2IHK, 2IHZ, 2II6, 2IIB, 2IIQ, and 2ILV.
References
edit- Rearick JI, Sadler JE, Paulson JC, Hill RL (1979). "Enzymatic characterization of beta D-galactoside alpha2 leads to 3 sialyltransferase from porcine submaxillary gland". J. Biol. Chem. 254 (11): 4444–51. doi:10.1016/S0021-9258(17)30029-7. PMID 438198.
- Sadler JE, Rearick JI, Paulson JC, Hill RL (1979). "Purification to homogeneity of a beta-galactoside alpha2 leads to 3 sialyltransferase and partial purification of an alpha-N-acetylgalactosaminide alpha2 leads to 6 sialyltransferase from porcine submaxillary glands". J. Biol. Chem. 254 (11): 4434–42. doi:10.1016/S0021-9258(17)30027-3. PMID 438196.
