Beta-1,4-galactosyltransferase 4 is an enzyme that in humans is encoded by the B4GALT4gene.[5][6]
This gene is one of seven beta-1,4-galactosyltransferase (beta4GalT) genes. They encode type II membrane-boundglycoproteins that appear to have exclusive specificity for the donor substrateUDP-galactose; all transfer galactose in a beta1,4 linkage to similar acceptor sugars: GlcNAc, Glc, and Xyl. Each beta4GalT has a distinct function in the biosynthesis of different glycoconjugates and saccharide structures. As type II membrane proteins, they have an N-terminalhydrophobicsignal sequence that directs the protein to the Golgi apparatus and which then remains uncleaved to function as a transmembrane anchor. By sequence similarity, the beta4GalTs form four groups: beta4GalT1 and beta4GalT2, beta4GalT3 and beta4GalT4, beta4GalT5 and beta4GalT6, and beta4GalT7. The enzyme encoded by this gene appears to mainly play a role in glycolipidbiosynthesis. Two alternatively spliced transcript variants have been found for this gene.[6]
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