3LPO, 3LPP647669983ENSG00000090402ENSMUSG00000027790P14410F8VQM5NM_001041NM_001081137NP_001032NP_001074606Sucrase-isomaltase is a bifunctional glucosidase (sugar-digesting enzyme) located on the brush border of the small intestine, encoded by the human gene SI.

[10] The enzyme is anchored in the intestinal brush border membrane by a hydrophobic segment located near the N-terminus of the isomaltase subunit.

[15] ntSI’s four monomers, A, B, C, and D are included in the crystal asymmetric unit and have identical active sites.

[15] The interactions between the active site of sucrase-isomaltase and the following compounds have been identified: Currently, there are no crystal structures of ntSI in complex with an α-1,6-linked substrate or inhibitor analogue.

In order to predict isomaltose binding in sucrase-isomaltase structure, a model was produced by hand.

These mutations cause a loss of enzyme function by blocking the biosynthesis of SI at the cell surface.