SclC is a member of a novel family of collagen-like proteins in Streptococcus equi subspecies equi that are recognised by antibodies against SclC

Vet Microbiol. 2006 Apr 16;114(1-2):72-81. doi: 10.1016/j.vetmic.2005.10.036. Epub 2005 Dec 27.

Abstract

Previously we have reported on a cell surface collagen-like protein, called SclC, from Streptococcus equi subspecies equi. In the present study we show that this protein is a member of a family of seven collagen-like proteins, called SclC-SclI in this subspecies. All proteins contain an N-terminal signal sequence, followed by a unique non-repetitive region called A, a highly repetitive collagen-like region (CL) consisting of Glycine-Xaa-Yaa-triplet repeats. Following the CL-region a C-terminal proline-rich putative wall spanning region (W) preceding an LPXTG-motif and a hydrophobic transmembrane region (M) are found, typical features of cell surface exposed proteins in Gram-positive bacteria. The nucleotide and amino acid sequences, were analysed to investigate the similarities between them, and recombinant proteins encoding different domains (A- and CL-regions) were expressed and purified. Although the novel collagen-like proteins display differences in amino acid sequences, affinity purified antibodies against SclC were found to cross react with the other members of the novel collagen-like proteins. Furthermore, in sera from horses previously diagnosed having strangles, antibodies against these proteins were detected suggesting that these proteins are expressed during the infection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Bacterial / blood
  • Collagen / classification
  • Collagen / genetics
  • Collagen / immunology*
  • DNA Primers / chemistry
  • Enzyme-Linked Immunosorbent Assay / veterinary
  • Gene Expression
  • Gene Order / genetics
  • Horse Diseases / immunology
  • Horse Diseases / microbiology
  • Horses
  • Imino Acids / analysis
  • Membrane Proteins / biosynthesis
  • Membrane Proteins / classification
  • Membrane Proteins / genetics*
  • Membrane Proteins / immunology*
  • Rabbits
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / genetics
  • Sequence Analysis, DNA
  • Streptococcal Infections / immunology
  • Streptococcal Infections / microbiology
  • Streptococcal Infections / veterinary*
  • Streptococcus equi / genetics*
  • Streptococcus equi / immunology
  • Streptococcus equi / metabolism

Substances

  • Antibodies, Bacterial
  • DNA Primers
  • Imino Acids
  • Membrane Proteins
  • Recombinant Proteins
  • Collagen