Electron microscopy and structural model of human fibronectin receptor

EMBO J. 1988 Dec 20;7(13):4093-9.

Abstract

Highly-purified human fibronectin receptor (a heterodimer of two distinct subunits, alpha and beta) was studied using electron microscopy and a variety of preparative procedures. It was found that the receptor consists of a globular head approximately 80 by 120 A and two tails about 20 A thick and 180-200 A long. The whole complex is approximately 280 A long. At low concentrations of detergent the receptor forms doublets, triplets or rosettes associated with the tails which possess the transmembrane portion of the molecule. Computer-assisted structure prediction using the published amino acid sequence of both subunits showed differences in the secondary structure of the tails, the alpha-tail being rich in beta-strands, the beta-tail having five cysteine-rich repeats analogous to the EGF-like repeats of laminin. Estimates of the length of the tails from the predicted structure conformed well with the dimensions obtained from electron micrographs.

MeSH terms

  • Amino Acid Sequence
  • Fibronectins / metabolism*
  • Humans
  • Microscopy, Electron
  • Models, Molecular
  • Molecular Sequence Data
  • Molecular Structure
  • Protein Conformation
  • Receptors, Fibronectin
  • Receptors, Immunologic*

Substances

  • Fibronectins
  • Receptors, Fibronectin
  • Receptors, Immunologic