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Identification and characterization of a new cell surface protein possessing factor H-binding activity in the swine pathogen and zoonotic agent Streptococcus suis
- Source :
- Journal of Medical Microbiology. 62:1073-1080
- Publication Year :
- 2013
- Publisher :
- Microbiology Society, 2013.
-
Abstract
- Streptococcus suis is a major swine pathogen and an emerging zoonotic agent. The ability of pathogenic bacteria to bind the complement regulator factor H on their cell surface may allow them to avoid complement attack and phagocytosis. The aim of this study was to characterize a new cell surface protein possessing factor H-binding activity in S. suis serotype 2. The capacity of S. suis to bind the complement regulator factor H on its surface was demonstrated by ELISA. Using a factor I–cofactor assay, it was found that the functional activity of factor H bound to S. suis was kept. Since the product of gene SSU0186 in S. suis P1/7 shared similarity with a Streptococcus pneumoniae protein (named PspC) possessing factor H-binding activity, it was proposed as a putative factor H receptor in S. suis. SSU0186 has a 1686 bp open reading frame encoding a 561 amino acid protein containing the Gram-positive cell wall anchoring motif (LPXTG) at the carboxy-terminal, an amino-terminal signal sequence, an α-helix domain, a proline-rich region and a G5 domain. The SSU0186 gene was cloned in Escherichia coli and the purified recombinant factor H-binding protein showed a molecular mass of 95 kDa, as determined by SDS-PAGE. The protein possessed the functional property of binding factor H. Sera from S. suis-infected pigs reacted with the recombinant factor H receptor, suggesting that it is produced during the course of infections. In conclusion, we identified a novel S. suis cell surface protein that binds the complement factor H. This cell surface protein may help S. suis to resist complement attack and phagocytosis and contribute to pathogenesis.
- Subjects :
- Microbiology (medical)
Signal peptide
Streptococcus suis
Swine
Plasma protein binding
Complement factor I
medicine.disease_cause
Microbiology
Bacterial Proteins
Zoonoses
medicine
Animals
Humans
Cloning, Molecular
Escherichia coli
Pathogen
biology
Membrane Proteins
Gene Expression Regulation, Bacterial
General Medicine
biology.organism_classification
Open reading frame
Complement Factor H
Factor H
Protein Binding
Subjects
Details
- ISSN :
- 14735644 and 00222615
- Volume :
- 62
- Database :
- OpenAIRE
- Journal :
- Journal of Medical Microbiology
- Accession number :
- edsair.doi.dedup.....8e6129835b2c3985c42672bdef9f7d30
- Full Text :
- https://doi.org/10.1099/jmm.0.057877-0