The crystal structure of the ligand binding module of axonin-1/TAG-1 suggests a zipper mechanism for neural cell adhesion

Cell. 2000 May 12;101(4):425-33. doi: 10.1016/s0092-8674(00)80852-1.


We have determined the crystal structure of the ligand binding fragment of the neural cell adhesion molecule axonin-1/TAG-1 comprising the first four immunoglobulin (Ig) domains. The overall structure of axonin-1(Ig1-4) is U-shaped due to contacts between domains 1 and 4 and domains 2 and 3. In the crystals, these molecules are aligned in a string with adjacent molecules oriented in an anti-parallel fashion and their C termini perpendicular to the string. This arrangement suggests that cell adhesion by homophilic axonin-1 interaction occurs by the formation of a linear zipper-like array in which the axonin-1 molecules are alternately provided by the two apposed membranes. In accordance with this model, mutations in a loop critical for the formation of the zipper resulted in the loss of the homophilic binding capacity of axonin-1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Adhesion
  • Cell Adhesion Molecules, Neuronal / chemistry*
  • Cell Adhesion Molecules, Neuronal / metabolism
  • Contactin 2
  • Humans
  • Ligands
  • Molecular Sequence Data
  • Neurons / cytology
  • Neurons / physiology*
  • Protein Binding
  • Protein Conformation*
  • Tumor Cells, Cultured


  • CNTN2 protein, human
  • Cell Adhesion Molecules, Neuronal
  • Contactin 2
  • Ligands

Associated data

  • PDB/1CS6