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Journal article

Cloning and characterization of two bistructural S-layer-RTX proteins from Campylobacter rectus.

  • 1999-04-10
Published in:
  • Journal of bacteriology. - 1999
Bacterial Outer Membrane Proteins
Bacterial Proteins
Bacterial Toxins
Campylobacter
Cloning, Molecular
Genes, Bacterial
Membrane Glycoproteins
Molecular Sequence Data
Protein Conformation
Repetitive Sequences, Amino Acid
Sequence Analysis, DNA
Species Specificity
English Campylobacter rectus is an important periodontal pathogen in humans. A surface-layer (S-layer) protein and a cytotoxic activity have been characterized and are thought to be its major virulence factors. The cytotoxic activity was suggested to be due to a pore-forming protein toxin belonging to the RTX (repeats in the structural toxins) family. In the present work, two closely related genes, csxA and csxB (for C. rectus S-layer and RTX protein) were cloned from C. rectus and characterized. The Csx proteins appear to be bifunctional and possess two structurally different domains. The N-terminal part shows similarity with S-layer protein, especially SapA and SapB of C. fetus and Crs of C. rectus. The C-terminal part comprising most of CsxA and CsxB is a domain with 48 and 59 glycine-rich canonical nonapeptide repeats, respectively, arranged in three blocks. Purified recombinant Csx peptides bind Ca2+. These are characteristic traits of RTX toxin proteins. The S-layer and RTX domains of Csx are separated by a proline-rich stretch of 48 amino acids. All C. rectus isolates studied contained copies of either the csxA or csxB gene or both; csx genes were absent from all other Campylobacter and Helicobacter species examined. Serum of a patient with acute gingivitis showed a strong reaction to recombinant Csx protein on immunoblots.
Language
  • English
Open access status
bronze
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https://sonar.ch/global/documents/185433
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