Structure of human ST8SiaIII sialyltransferase provides insight into cell-surface polysialylation

Nat Struct Mol Biol. 2015 Aug;22(8):627-35. doi: 10.1038/nsmb.3060. Epub 2015 Jul 20.


Sialyltransferases of the mammalian ST8Sia family catalyze oligo- and polysialylation of surface-localized glycoproteins and glycolipids through transfer of sialic acids from CMP-sialic acid to the nonreducing ends of sialic acid acceptors. The crystal structure of human ST8SiaIII at 1.85-Å resolution presented here is, to our knowledge, the first solved structure of a polysialyltransferase from any species, and it reveals a cluster of polysialyltransferase-specific structural motifs that collectively provide an extended electropositive surface groove for binding of oligo-polysialic acid chain products. The ternary complex of ST8SiaIII with a donor sugar analog and a sulfated glycan acceptor identified with a sialyltransferase glycan array provides insight into the residues involved in substrate binding, specificity and sialyl transfer.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Binding Sites / genetics
  • Cells, Cultured
  • Chromatography, Thin Layer
  • Crystallography, X-Ray
  • Electrophoresis, Polyacrylamide Gel
  • Glycosylation
  • Humans
  • Kinetics
  • Mass Spectrometry / methods
  • Models, Molecular
  • Molecular Sequence Data
  • Mutation
  • Neural Cell Adhesion Molecules / chemistry
  • Neural Cell Adhesion Molecules / genetics
  • Neural Cell Adhesion Molecules / metabolism
  • Polysaccharides / chemistry
  • Polysaccharides / metabolism
  • Protein Binding
  • Protein Structure, Tertiary*
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / metabolism
  • Sequence Homology, Amino Acid
  • Sialic Acids / chemistry
  • Sialic Acids / metabolism*
  • Sialyltransferases / chemistry*
  • Sialyltransferases / genetics
  • Sialyltransferases / metabolism*


  • Neural Cell Adhesion Molecules
  • Polysaccharides
  • Recombinant Proteins
  • Sialic Acids
  • polysialic acid
  • Sia(alpha2,3)Gal(beta1,4)GlcNAc alpha-2,8-sialyltransferase
  • Sialyltransferases