| Type: | Family | Name: | Glycosyl transferase, family 2, hopene-associated, HpnB |
| Description: | The biosynthesis of disaccharides, oligosaccharides and polysaccharides involves the action of hundreds of different glycosyltransferases. These enzymes catalyse the transfer of sugar moieties from activated donor molecules to specific acceptor molecules, forming glycosidic bonds. A classification of glycosyltransferases using nucleotide diphospho-sugar, nucleotide monophospho-sugar and sugar phosphates () and related proteins into distinct sequence based families has been described []. This classification is available on the CAZy (CArbohydrate-Active EnZymes) web site. The same three-dimensional fold is expected to occur within each of the families. Because 3-D structures are better conserved than sequences, several of the families defined on the basis of sequence similarities may have similar 3-D structures and therefore form 'clans'.Proteins in this entry contain glycosyl transferase family 2 domains which are responsible, generally, for the transfer of nucleotide-diphosphate sugars to substrates such as polysaccharides and lipids. These proteins are often encoded in the same genetic locus as squalene-hopene cyclase genes, and are never associated with genes for the metabolism of phytoene. Indeed, proteins in this entry appear to never be encoded in a genome lacking squalene-hopene cyclase (SHC), although not all genomes encoding SHC have this glycosyl transferase. In the organism Zymomonas mobilisthe linkage of this protein to hopanoid biosynthesis has been noted and it was named HpnB []. Hopanoids are known to feature polar glycosyl head groups in many organisms. | Short Name: | Glyco_trans_2_hopen-assoc_HpnB |
