Streptococcus Mutans Strains Harboring Collagen-Binding Adhesin

J Dent Res. 2004 Jul;83(7):534-9. doi: 10.1177/154405910408300705.


A previously unidentified 120-kDa protein was detected in Streptococcus mutans strain Z1 and was involved in the cold-agglutination of the strain. We have identified the gene, designated cnm, as being involved in the agglutination of strain Z1 following random mutagenesis. The amino acid sequence of the deduced Cnm protein exhibited high similarity to those of collagen-binding adhesins from staphylococci and other organisms. To confirm whether the protein is involved in collagen-binding, we cloned a cnm gene fragment, overexpressed it in E.coli, and prepared crude extracts. The extracts containing recombinant protein exhibited binding to immobilized collagen and laminin but not to fibronectin. Compared with the parental strain Z1, the cold-agglutination-negative mutant 05A02 exhibited reduced binding to collagen and laminin but retained that to fibronectin. This gene was detected in some strains of S. mutans. Therefore, the cnm gene encoded a new strain-specific member of the collagen-binding adhesin family.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adhesins, Bacterial / genetics*
  • Adhesins, Bacterial / metabolism*
  • Amino Acid Sequence
  • Base Sequence
  • Blotting, Southern
  • Carrier Proteins / genetics*
  • Carrier Proteins / metabolism*
  • Cloning, Molecular
  • Collagen / metabolism
  • Genes, Bacterial*
  • Molecular Sequence Data
  • Mutagenesis
  • Sequence Homology
  • Species Specificity
  • Streptococcus mutans / classification
  • Streptococcus mutans / genetics*
  • Streptococcus mutans / metabolism*


  • Adhesins, Bacterial
  • Carrier Proteins
  • Cnm protein, Streptococcus mutans
  • Collagen

Associated data

  • GENBANK/AB102869