Localization and characterization of VVA0331, a 489-kDa RTX-like protein, in Vibrio vulnificus YJ016

Abstract

Vibrio vulnificus YJ016 contains three genes encoding proteins homologous to repeats-in-toxin proteins. One of these genes, vva0331, possesses a long open reading frame of 13,971 bp in length and resides on the small chromosome between two gene clusters encoding a type I secretion system and several regulatory proteins, respectively. Bioinformatic analysis revealed that VVA0331 consist of nineteen 87-amino acid repeats, two Arg-Gly-Asp motifs, four cysteine residues, an outer membrane protein domain, a polysaccharide-binding site and several motifs related to cell adhesions. These features are distinct from those of typical repeat-in-toxins and autotransporter adhesins. Real-time quantitative PCR analysis indicates that vva0331 gene expression is activated at 30 degrees C and regulated by iron. In addition, VVA0331 is present primarily in a secreted form as determined by cell fractionation assay and Western blot analysis. No significant difference in Hep2 cell adherence, cytotoxicity, and virulence was observed between the wild type and vva0331 mutant strains. In contrast, these strains exhibited apparently different outer membrane protein profiles, and antiserum raised against C-terminal region of VVA0331 reacted with an 85-kDa outer membrane protein of V. vulnificus YJ016.

Genotypic Diversity and Virulence Characteristics of Clinical and Environmental Vibrio vulnificus Isolates from the Baltic Sea Region

“…Furthermore, oligonucleotide primers for three potential virulence genes located in a 53-kb region of chromosome II (21) were designed and applied in PCR assays: open reading frames (ORFs) VVA0303, encoding a putative thermolabile hemolysin, VVA0320, encoding a zinc-dependent hydrolase, and VVA0331, encoding a 489-kDa RTX-like protein (43). These results are not displayed in Table 5 because all strains were positive for VVA0303 and VVA0320 and only strains VN-0016, VN-0105, VN-0120, VN-0206, and VN-0207 were negative for VVA0331.…”

RTX Adhesins are Key Bacterial Surface Megaproteins in the Formation of Biofilms

“…Matter & the Laboratory of Macromolecular and Organic Chemistry of the Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Eindhoven, 5600MD the Netherlands 2 From the Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario K7L 3N6, Canada Many Gram-negative bacteria produce Repeats-In-Toxin adhesion proteins (RTX adhesins) to facilitate microbial adhesion to a variety of biotic and abiotic substrates. These large, multidomain proteins share a common architecture comprised of four regions that have been deduced through a combination of bioinformatics and structure-function studies (Figure 1).…”