title: The spvB gene-product of the Salmonella enterica virulence plasmid is a mono(ADP-ribosyl)transferase.
abstract: A number of well-known bacterial toxins ADP-ribosylate and thereby inactivate target proteins in their animal hosts. Recently, several vertebrate ecto-enzymes (ART1-ART7) with activities similar to bacterial toxins have also been cloned. We show here that PSIBLAST, a position-specific-iterative database search program, faithfully connects all known vertebrate ecto-mono(ADP-ribosyl)transferases (mADPRTs) with most of the known bacterial mADPRTs. Intriguingly, no matches were found in the available public genome sequences of archaeabacteria, the yeast Saccharomyces cerevisiae or the nematode Caenorhabditis elegans. Significant new matches detected by PSIBLAST from the public sequence data bases included only one open reading frame (ORF) of previously unknown function: the spvB gene contained in the virulence plasmids of Salmonella enterica. Structure predictions of SpvB indicated that it is composed of a C-terminal ADP-ribosyltransferase domain fused via a poly proline stretch to a N-domain resembling the N-domain of the secretory toxin TcaC from nematode-infecting enterobacteria. We produced the predicted catalytic domain of SpvB as a recombinant fusion protein and demonstrate that it, indeed, acts as an ADP-ribosyltransferase. Our findings underscore the power of the PSIBLAST program for the discovery of new family members in genome databases. Moreover, they open a new avenue of investigation regarding salmonella pathogenesis.
authors.affiliation: Institute for Immunology, University Hospital, Martinistr. 52, D-20246 Hamburg, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Otto
authors.forename: D
authors.initials: D
authors.lastname: Tezcan-Merdol
authors.forename: R
authors.initials: R
authors.lastname: Girisch
authors.forename: F
authors.initials: F
authors.lastname: Haag
authors.forename: M
authors.initials: M
authors.lastname: Rhen
authors.forename: F
authors.initials: F
authors.lastname: Koch-Nolte
mesh_terms: D036002:ADP Ribose Transferases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D002384:Catalysis; D020134:Catalytic Domain; D002457:Cell Extracts; D016208:Databases, Factual; D015870:Gene Expression; D006801:Humans; D019169:Jurkat Cells; D051379:Mice; D008969:Molecular Sequence Data; D010957:Plasmids; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D019779:Salmonella enterica / Q000201:enzymology* / Q000235:genetics / Q000472:pathogenicity; D017386:Sequence Homology, Amino Acid; D013879:Thioredoxins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D014714:Vertebrates / Q000235:genetics; D014774:Virulence; D037521:Virulence Factors
chemical_list: D002457:Cell Extracts; D011993:Recombinant Fusion Proteins; D037521:Virulence Factors; D013879:Thioredoxins; D036002:ADP Ribose Transferases; C415223:spvB protein, Salmonella enterica virulence plasmid