This family contains the bacterial enzyme alpha-2,8-polysialyltransferase (EC:2.4.99.-) (approximately 500 residues long). This catalyses the polycondensation of alpha-2,8-linked sialic acid required for the synthesis of polysialic acid (PSA) [1].

1: Functional relationships of the sialyltransferases involved in expression of the polysialic acid capsules of Escherichia coli K1 and K92 and Neisseria meningitidis groups B or C. Steenbergen SM, Vimr ER; J Biol Chem 2003;278:15349-15359. PMID:12578835