Glycoside hydrolase family 5

Cellulase (glycosyl hydrolase family 5)
Identifiers
Symbol	Cellulase
Pfam	PF00150
Pfam clan	CL0058
InterPro	IPR001547
PROSITE	PDOC00565
SCOP	2exo
SUPERFAMILY	2exo
OPM superfamily	125
OPM protein	2osx
CAZy	GH5
Available protein structures: Pfam structures PDB RCSB PDB; PDBe; PDBj PDBsum structure summary

In molecular biology, glycoside hydrolase family 5 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/Glycoside-Hydrolases.html) web site,^[4] and also discussed at CAZypedia, an online encyclopedia of carbohydrate active enzymes.^[5]

Glycoside hydrolase family 5 CAZY GH_5 comprises enzymes with several known activities including endoglucanase (EC 3.2.1.4); beta-mannanase (EC 3.2.1.78); exo-1,3-glucanase (EC 3.2.1.58); endo-1,6-glucanase (EC 3.2.1.75); xylanase (EC 3.2.1.8); endoglycoceramidase (EC 3.2.1.123).

The microbial degradation of cellulose and xylans requires several types of enzymes. Fungi and bacteria produces a spectrum of cellulolytic enzymes (cellulases) and xylanases which, on the basis of sequence similarities, can be classified into families. One of these families is known as the cellulase family A^[6] or as the glycosyl hydrolases family 5.^[7] One of the conserved regions in this family contains a conserved glutamic acid residue which is potentially involved^[8] in the catalytic mechanism.

In a recent study using Molecular Dynamics simulations, a considerable correlation between thermal stability and structural rigidity of members of family 5 with solved structures has been proved.^[9]

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. Henrissat B, Tomme P, Claeyssens M, Mornon JP, Lemesle L (1989). "Cellulase families revealed by hydrophobic cluster analysis". Gene 81 (1): 83–95. doi:10.1016/0378-1119(89)90339-9. PMID 2806912.
7. Henrissat B (1991). "A classification of glycosyl hydrolases based on amino acid sequence similarities". Biochem. J. 280: 309–316. PMC 1130547. PMID 1747104.
8. Haiech J, Chippaux M, Barras F, Py B, Bortoli-German I (1991). "Cellulase EGZ of Erwinia chrysanthemi: structural organization and importance of His98 and Glu133 residues for catalysis". Protein Eng. 4 (3): 325–333. doi:10.1093/protein/4.3.325. PMID 1677466.
9. Badieyan, S; Bevan DR; Zhang C (January 2012). "Study and design of stability in GH5 cellulases.". Biotechnology and Bioengineering 109 (1): 31–44. doi:10.1002/bit.23280. PMID 21809329.