Glycoside hydrolase family 15

Glycosyl hydrolases family 15
Identifiers
Symbol Glyco_hydro_15
Pfam PF00723
Pfam clan CL0059
SCOP 1glm
CAZy GH15

In molecular biology, glycoside hydrolase family 15 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]

Glycoside hydrolase family 15 CAZY GH_15 comprises enzymes with several known activities; glucoamylase (EC 3.2.1.3); alpha-glucosidase (EC 3.2.1.20); glucodextranase (EC 3.2.1.70).

Glucoamylase (GA) catalyses the release of D-glucose from the non-reducing ends of starch and other oligo- or poly-saccharides. Studies of fungal GA have indicated 3 closely clustered acidic residues that play a role in the catalytic mechanism.[6] This region is also conserved in a recently sequenced bacterial GA.[7]

The 3D structure of the pseudo-tetrasaccharide acarbose complexed with glucoamylase II(471) from Aspergillus awamori var. X100 has been determined to 2.4A resolution.[8] The protein belongs to the mainly alpha class, and contains 19 helices and 9 strands.

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. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=41477. 
  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. ^ Svensson B, Ford C, Sierks MR, Reilly PJ (1990). "Catalytic mechanism of fungal glucoamylase as defined by mutagenesis of Asp176, Glu179 and Glu180 in the enzyme from Aspergillus awamori". Protein Eng. 3 (3): 193–198. doi:10.1093/protein/3.3.193. PMID 1970434. 
  7. ^ Ohnishi H, Kitamura H, Minowa T, Sakai H, Ohta T (1992). "Molecular cloning of a glucoamylase gene from a thermophilic Clostridium and kinetics of the cloned enzyme". Eur. J. Biochem. 207 (2): 413–418. doi:10.1111/j.1432-1033.1992.tb17064.x. PMID 1633799. 
  8. ^ Aleshin AE, Firsov LM, Honzatko RB (1994). "Refined structure for the complex of acarbose with glucoamylase from Aspergillus awamori var. X100 to 2.4-A resolution". J. Biol. Chem. 269 (22): 15631–15639. PMID 8195212.