GO curators for mouse genes have assigned the following annotations to the gene product of B3galt5. (This text reflects annotations as of Wednesday, January 23, 2013.) Summary from NCBI RefSeq
[Summary is not available for the mouse gene. This summary is for the human ortholog.] This gene is a member of the beta-1,3-galactosyltransferase (beta3GalT) gene family. This family encodes type II membrane-bound glycoproteins with diverse enzymatic functions using different donor substrates (UDP-galactose and UDP-N-acetylglucosamine) and different acceptor sugars (N-acetylglucosamine, galactose, N-acetylgalactosamine). The beta3GalT genes are distantly related to the Drosophila Brainiac gene and have the protein coding sequence contained in a single exon. The beta3GalT proteins also contain conserved sequences not found in the beta4GalT or alpha3GalT proteins. The carbohydrate chains synthesized by these enzymes are designated as type 1, whereas beta4GalT enzymes synthesize type 2 carbohydrate chains. The ratio of type 1:type 2 chains changes during embryogenesis. By sequence similarity, the beta3GalT genes fall into at least two groups: beta3GalT4 and 4 other beta3GalT genes (beta3GalT1-3, beta3GalT5). This gene encodes the most probable candidate for synthesis of the type 1 Lewis antigens which are frequently found to be elevated in gastrointestinal and pancreatic cancers. The encoded protein is inactive with N-linked glycoproteins and functions in mucin glycosylation. Alternatively spliced transcript variants encoding the same protein have been observed for this gene. [provided by RefSeq, Jul 2012]Summary text based on GO annotations supported by experimental evidence in other organisms
From comparative sequence analysis (see table for details), MGI curators have determined that the gene product of B3galt5: