Glycoside hydrolase family 7 explained

Symbol:	Glyco_hydro_7
Glycosyl hydrolase family 7
Pfam:	PF00840
Pfam Clan:	CL0004
Interpro:	IPR001722
Scop:	1cel
Cazy:	GH7
Cdd:	cd07999

In molecular biology, glycoside hydrolase family 7 is a family of glycoside hydrolases, which 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 web site,^{[4] [5]} and also discussed at CAZypedia, an online encyclopedia of carbohydrate active enzymes.^{[6] [7]}

Glycoside hydrolase family 7 CAZY GH_7 comprises enzymes with several known activities including endoglucanase and cellobiohydrolase . These enzymes were formerly known as cellulase family C.

Exoglucanases and cellobiohydrolases^[8] play a role in the conversion of cellulose to glucose by cutting the disaccharide cellobiose from the non-reducing end of the cellulose polymer chain. Structurally, cellulases and xylanases frequently consist of a catalytic domain joined to a cellulose-binding domain (CBD) via a linker region that is rich in proline and/or hydroxy-amino acids. In type I exoglucanases, the CBD domain is found at the C-terminal extremity of these enzyme (this short domain forms a hairpin loop structure stabilised by 2 disulphide bridges).

Notes and References

1. Henrissat B, Callebaut I, Fabrega S, Lehn P, Mornon JP, Davies G . Conserved catalytic machinery and the prediction of a common fold for several families of glycosyl hydrolases . Proceedings of the National Academy of Sciences of the United States of America . 92 . 15 . 7090–4 . July 1995 . 7624375 . 41477 . 10.1073/pnas.92.15.7090 . 1995PNAS...92.7090H . free .
2. Davies G, Henrissat B . Structures and mechanisms of glycosyl hydrolases . Structure . 3 . 9 . 853–9 . September 1995 . 8535779 . 10.1016/S0969-2126(01)00220-9 . free .
3. Henrissat B, Bairoch A . Updating the sequence-based classification of glycosyl hydrolases . The Biochemical Journal . 316 . Pt 2 . 695–6 . June 1996 . 8687420 . 1217404 . 10.1042/bj3160695.
4. Web site: Home. CAZy.org. en. 2018-03-06.
5. Lombard V, Golaconda Ramulu H, Drula E, Coutinho PM, Henrissat B . The carbohydrate-active enzymes database (CAZy) in 2013 . Nucleic Acids Research . 42 . Database issue . D490–5 . January 2014 . 24270786 . 3965031 . 10.1093/nar/gkt1178 .
6. Web site: Glycoside Hydrolase Family 7. CAZypedia.org. en. 2018-03-06.
7. Ten years of CAZypedia: a living encyclopedia of carbohydrate-active enzymes . Glycobiology . 28 . 1 . 3–8 . December 2018 . 29040563 . 10.1093/glycob/cwx089 . CAZypedia Consortium . free .
8. Gilkes NR, Henrissat B, Kilburn DG, Miller RC, Warren RA . Domains in microbial beta-1, 4-glycanases: sequence conservation, function, and enzyme families . Microbiological Reviews . 55 . 2 . 303–15 . June 1991 . 10.1128/MMBR.55.2.303-315.1991 . 1886523 . 372816 .