InterPro: IPR005196 Glycoside hydrolase family 65, N-terminal

O-Glycosyl 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 glycosyl hydrolases, based on sequence similarity, has led to the definition of 85 different families [1, 2, 3]. This classification is available on the CAZy (CArbohydrate-Active EnZymes) web site [4]. Because the fold of proteins is better conserved than their sequences, some of the families can be grouped in clans.

The family of glycosyl hydrolases (GH65) containing this domain includes vacuolar acid trehalase and maltose phosphorylase. Maltose phosphorylase (MP) is a dimeric enzyme that catalyzes the conversion of maltose and inorganic phosphate into beta-D-glucose-1-phosphate and glucose. This domain is believed to be essential for catalytic activity [5] although its precise function remains unknown.