Glycosyltransferase family 52. This family features glycosyltransferases belonging to glycosyltransferase family 52, which have alpha-2,3- sialyltransferase (EC:4.2.99.4) and alpha-glucosyltransferase (EC 2.4.1.-) activity. For example, beta-galactoside alpha-2,3- sialyltransferase expressed by Neisseria meningitidis is a member of this family and is involved in a step of lipooligosaccharide biosynthesis requiring sialic acid transfer; these lipooligosaccharides are thought to be important in the process of pathogenesis. This family includes several bacterial lipooligosaccharide sialyltransferases similar to the Haemophilus ducreyi LST protein. Haemophilus ducreyi is the cause of the sexually transmitted disease chancroid and produces a lipooligosaccharide (LOS) containing a terminal sialyl N-acetyllactosamine trisaccharide.
Alpha-2,8-polysialyltransferase (POLYST). This family contains the bacterial enzyme alpha-2,8-polysialyltransferase (EC:2.4.99.-) (approximately 500 residues long). This catalyzes the polycondensation of alpha-2,8-linked sialic acid required for the synthesis of polysialic acid (PSA).