B4GALT7 gene encodes the seventh member of the human beta4-galactosyltransferase family (beta4Gal-T). By sequence similarity, the beta4GalTs form four groups: beta4GalT1 and beta4GalT2, beta4GalT3 and beta4GalT4, beta4GalT5 and beta4GalT6, and beta4GalT7. The genes of this family encode type II membrane-bound glycoproteins that appear to have exclusive specificity for the donor substrate UDP-galactose; all transfer galactose in a beta 1,4 linkage to similar acceptor sugars: GlcNAc, Glc, and Xyl. Each beta4GalT has a distinct function in the biosynthesis of different glycoconjugates and saccharide structures. The enzyme encoded by B4GALT7 gene attaches the first galactose in the common carbohydrate-protein (GlcA-beta1,3-Gal-beta1,3-Gal-beta1,4-Xyl-beta1-O-Ser) linkage found in glycosaminoglycan (GAG) chains which make up proteoglycans (PGs). PGs which are located at cell surfaces and in extracellular matrix are thought to be involved in many biological processes such as cell proliferation/differentiation, cell adhesion, tissue development, organogenesis, blood coagulation, and wound repair. In most cases, biological activities of PGs are governed by interactions of their GAG chains with growth factors, cytokines, morphogens, and a variety of protein ligands. Accordingly, the disruption of the glycosyltransferases involved in either initiation or elongation of their GAG chains has severe biological consequences. In human, mutations of the B4GALT7 gene cause a progeroid variant of Ehlers-Danlos syndrome.

B4GALT7 gene is located on the long arm of chromosome 5 at 5q35.2-q35.3. It consists of six exons. The B4GALT7 protein is 327 amino acids long and weighs approximately 37,405.73Da. This protein is expressed in high level in heart, pancreas and liver, medium level in placenta and kidney, low level in brain, skeletal muscle and lung. As type II membrane proteins, it has an N-terminal hydrophobic signal sequence that directs the protein to the Golgi apparatus and which then remains uncleaved to function as a transmembrane anchor. This enzyme differs from the other six beta4GalTs because it lacks the conserved beta4GalT1-beta4GalT6 Cys residues and it is located in cis-Golgi instead of trans-Golgi.