MGAM

This gene encodes maltase-glucoamylase, which is a brush border membrane enzyme that plays a role in the final steps of digestion of starch. The protein has two catalytic sites identical to those of sucrase-isomaltase, but the proteins are only 59% homologous. Both are members of glycosyl hydrolase family 31, which has a variety of substrate specificities.

Full Name

MGAM

Function

Alpha-(1,4) exo-glucosidase involved in breakdown of dietary starch oligosaccharides in small intestine. Cleaves the non-reducing alpha-(1,4)-linked glucose residue in linear dextrins with retention of anomeric center stereochemistry (PubMed:12547908, PubMed:18356321, PubMed:27480812, PubMed:18036614, PubMed:22058037).

Mainly hydrolyzes short length oligomaltoses having two to seven glucose residues (PubMed:12547908, PubMed:18356321, PubMed:27480812, PubMed:18036614, PubMed:22058037).

Can cleave alpha-(1,2), alpha-(1,3) and alpha-(1,6) glycosidic linkages with lower efficiency, whereas beta glycosidic linkages are usually not hydrolyzed (PubMed:27480812).

Biological Process

Dextrin catabolic process Source: UniProtKB
Maltose catabolic process Source: UniProtKB
Starch catabolic process Source: ProtInc

Cellular Location

Plasma membrane
Apical cell membrane
Note: Brush border.

Topology

Cytoplasmic: 1-13
Helical: 14-34
Lumenal: 35-2753

PTM

N- and O-glycosylated.
Does not undergo intracellular or extracellular proteolytic cleavage.
Sulfated.