Glycoside hydrolase family 33

Sialidase, N-terminal domain
Identifiers
Symbol	Sialidase
Pfam	PF02973
InterPro	IPR004124
SCOP	1sli
SUPERFAMILY	1sli
CAZy	GH33
Available protein structures: Pfam structures PDB RCSB PDB; PDBe; PDBj PDBsum structure summary

In molecular biology, glycoside hydrolase family 33 is a family of glycoside hydrolases.

Glycoside hydrolases EC 3.2.1. are a widespread group of enzymes that hydrolyse the glycosidic bond between two or more carbohydrates, or between a carbohydrate and a non-carbohydrate moiety. A classification system for glycoside hydrolases, based on sequence similarity, has led to the definition of >100 different families.^[1][2][3] This classification is available on the CAZy(http://www.cazy.org/GH1.html) web site,^[4] and also discussed at CAZypedia, an online encyclopedia of carbohydrate active enzymes.^[5]

This family contains sialidases (CAZY GH_33), which hydrolyse alpha-(2->3)-, alpha-(2->6)-, alpha-(2->8)-glycosidic linkages of terminal sialic residues in oligosaccharides, glycoproteins, glycolipids, colominic acid and synthetic substrates. Sialidases may act as pathogenic factors in microbial infections.^[6] The 1.8 A structure of trans-sialidase from leech (Macrobdella decora, Q27701) in complex with 2-deoxy-2, 3-didehydro-NeuAc was solved. The refined model comprising residues 81-769 has a catalytic beta-propeller domain, a N-terminal lectin-like domain and an irregular beta-stranded domain inserted into the catalytic domain.^[7]

References

1. Henrissat B, Callebaut I, Mornon JP, Fabrega S, Lehn P, Davies G (1995). "Conserved catalytic machinery and the prediction of a common fold for several families of glycosyl hydrolases". Proc. Natl. Acad. Sci. U.S.A. 92 (15): 7090–7094. doi:10.1073/pnas.92.15.7090. PMC 41477. PMID 7624375.
2. Henrissat B, Davies G (1995). "Structures and mechanisms of glycosyl hydrolases". Structure 3 (9): 853–859. doi:10.1016/S0969-2126(01)00220-9. PMID 8535779.
3. Bairoch, A. "Classification of glycosyl hydrolase families and index of glycosyl hydrolase entries in SWISS-PROT". 1999.
4. Henrissat, B. and Coutinho P.M. "Carbohydrate-Active Enzymes server". 1999.
5. CAZypedia, an online encyclopedia of carbohydrate-active enzymes.
6. Rothe B, Rothe B, Roggentin P, Schauer R (1991). "The sialidase gene from Clostridium septicum: cloning, sequencing, expression in Escherichia coli and identification of conserved sequences in sialidases and other proteins". Mol. Gen. Genet. 226 (1–2): 190–197. doi:10.1007/BF00273603. PMID 2034213.
7. Luo M, Luo Y, Li SC, Chou MY, Li YT (1998). "The crystal structure of an intramolecular trans-sialidase with a NeuAc alpha2-->3Gal specificity". Structure 6 (4): 521–530. doi:10.1016/S0969-2126(98)00053-7. PMID 9562562.