| Symbol: | Glyco_hydro_65N |
| Glycosyl hydrolase family 65, N-terminal domain | |
| Pfam: | PF03636 |
| Pfam Clan: | CL0103 |
| Interpro: | IPR005196 |
| Scop: | 1h54 |
| Cazy: | GH65 |
| Symbol: | Glyco_hydro_65m |
| Glycosyl hydrolase family 65 central catalytic domain | |
| Pfam: | PF03632 |
| Pfam Clan: | CL0059 |
| Interpro: | IPR005195 |
| Scop: | 1h54 |
| Cazy: | GH65 |
| Symbol: | Glyco_hydro_65C |
| Glycosyl hydrolase family 65, C-terminal domain | |
| Pfam: | PF03633 |
| Interpro: | IPR005194 |
| Scop: | 1h54 |
| Cazy: | GH65 |
In molecular biology, glycoside hydrolase family 65 is a family of glycoside hydrolases.
Glycoside hydrolases 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]
This family of glycosyl hydrolases (CAZY GH_65) includes vacuolar acid trehalase and maltose phosphorylases. Maltose phosphorylase (MP) is a dimeric enzyme that catalyzes the conversion of maltose and inorganic phosphate into beta-D-glucose-1-phosphate and glucose.
It consists of three structural domains. The C-terminal domain forms a two layered jelly roll motif. This domain is situated at the base of the catalytic domain, however its function remains unknown.[8] The central domain is the catalytic domain, which binds a phosphate ion that is proximal the highly conserved Glu. The arrangement of the phosphate and the glutamate is thought to cause nucleophilic attack on the anomeric carbon atom.[8] The catalytic domain also forms the majority of the dimerisation interface. The N-terminal domain is believed to be essential for catalytic activity[8] although its precise function remains unknown.