Background: Pasteurella pneumotropica is a ubiquitous bacterium that is frequently isolated from laboratory rodents and causes various clinical symptoms in immunodeficient animals. Currently two RTX toxins, PnxIA and PnxIIA, which are similar to hemolysin-like high-molecular-weight exoproteins are known in this species. In this study, we identified and analyzed a further RTX toxin named PnxIIIA and the corresponding type I secretion system.
Results: The RTX exoprotein, PnxIIIA, contains only a few copies of the RTX repeat-like sequence and 3 large repeat sequences that are partially similar to the outer membrane protein found in several prokaryotes. Recombinant PnxIIIA protein (rPnxIIIA) was cytotoxic toward J774A.1 mouse macrophage cells, whereas cytotoxicity was attenuated by the addition of anti-CD11a monoclonal antibody. rPnxIIIA could bind to extracellular matrices (ECMs) and cause hemagglutination of sheep erythrocytes. Binding was dependent on the 3 large repeat sequences in PnxIIIA. Protein interaction analyses indicated that PnxIIIA is mainly localized in the outer membrane of P. pneumotropica ATCC 35149 in a self-assembled oligomeric form. PnxIIIA is less cytotoxic to J774A.1 cells than PnxIA and PnxIIA.
Conclusions: The results implicate that PnxIIIA is located on the cell surface and participates in adhesion to ECMs and enhanced hemagglutination in the rodent pathogen P. pneumotropica.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3075217 | PMC |
| http://dx.doi.org/10.1186/1471-2180-11-55 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
The Actinobacillus pleuropneumoniae apxIV operon encodes an antibacterial toxin-immunity pair.
Microbiol Res
December 2024
Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, Prague 142 00, Czech Republic. Electronic address:
The ApxIVA protein belongs to a distinct class of a "clip and link" activity of Repeat-in-ToXin (RTX) exoproteins. Along with the three other pore-forming RTX toxins (ApxI, ApxII and ApxIII), ApxIVA serves as a major virulence factor of Actinobacillus pleuropneumoniae, the causative agent of porcine pneumonia. The gene encoding ApxIVA is located on a bicistronic operon downstream of the orf1 gene and is expressed exclusively under in vivo conditions.
View Article and Find Full Text PDFCalcium-induced structural transitions are central to the folding, function, and processing of serratiopeptidase zymogen into mature form.
FEBS J
May 2024
Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, India.
Serratia marcescens is an emerging health-threatening, gram-negative opportunistic pathogen associated with a wide variety of localized and life-threatening systemic infections. One of the most crucial virulence factors produced by S. marcescens is serratiopeptidase, a 50.
View Article and Find Full Text PDFInteraction of RTX toxins with the host cell plasma membrane.
Biol Chem
June 2023
Institute of Biochemistry, Heinrich-Heine-University Düsseldorf, Universitätsstr. 1, D-40225 Düsseldorf, Germany.
epeats in oins (RTX) protein family is a group of exoproteins secreted by Type 1 secretion system (T1SS) of several Gram-negative bacteria. The term RTX is derived from the characteristic nonapeptide sequence (GGxGxDxUx) present at the C-terminus of the protein. This RTX domain binds to calcium ions in the extracellular medium after being secreted out of the bacterial cells, and this facilitates folding of the entire protein.
View Article and Find Full Text PDFProteomic and immunoproteomic insights into the exoproteome of Actinobacillus pleuropneumoniae, the causative agent of porcine pleuropneumonia.
Microb Pathog
November 2022
Institute of Microbiology, Department for Pathobiology, University of Veterinary Medicine Vienna, Austria. Electronic address:
Porcine pleuropneumonia caused by Actinobacillus pleuropneumoniae affects pig health status and the swine industry worldwide. Despite the extensive number of studies focused on A. pleuropneumoniae infection and vaccine development, a thorough analysis of the A.
View Article and Find Full Text PDFStructural Basis of Ca-Dependent Self-Processing Activity of Repeat-in-Toxin Proteins.
mBio
March 2020
Laboratory of Molecular Biology of Bacterial Pathogens, Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
The posttranslational Ca-dependent "clip-and-link" activity of large epeat-in-oin (RTX) proteins starts by Ca-dependent structural rearrangement of a highly conserved self-processing module (SPM). Subsequently, an internal aspartate-proline (Asp-Pro) peptide bond at the N-terminal end of SPM breaks, and the liberated C-terminal aspartyl residue can react with a free ε-amino group of an adjacent lysine residue to form a new isopeptide bond. Here, we report a solution structure of the calcium-loaded SPM (Ca-SPM) derived from the FrpC protein of The Ca-SPM structure defines a unique protein architecture and provides structural insight into the autocatalytic cleavage of the Asp-Pro peptide bond through a "twisted-amide" activation.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!