title: Yersinia adhesin A (YadA)--beauty & beast.
abstract: The trimeric autotransporter adhesin Yersinia adhesin A is the prototype of the type Vc secretion systems. It is expressed by enteropathogenic Yersinia enterocolitica and Yersinia pseudotuberculosis strains, but not by Yersinia pestis. A characteristic trait of YadA is its modular composition and trimeric nature. YadA consists of an N-terminal passenger domain which is exposed on the bacterial cell surface. The translocation of this passenger onto the surface is facilitated by a C-terminal β-barrel domain which concomitantly anchors YadA into the outer membrane with three YadA monomers contributing to the formation of a single β-barrel. In Y. enterocolitica, but not Y. pseudotuberculosis, YadA is a decisive virulence factor and its deletion renders the bacteria virtually avirulent in mouse models of infection. This striking importance of YadA in infection may derive from its manifold functions in host cell interaction. Presumably the most important function of YadA is that it mediates adhesion to extracellular matrix components of eukaryotic host cells. Only tight adhesion allows for the injection of "anti-host" effector proteins via a type III secretion system into the host cell cytosol. These effector proteins enable Yersinia to subvert the host immune system in order to replicate and establish infection. YadA is also essential for the survival of Y. enterocolitica upon contact with serum, an important immune-evasion mechanism called serum resistance. To this end, YadA interacts with several components of the host complement system, the first line of immune defense. This review will summarize recent findings about the structure and biogenesis of YadA and its interactions with the host complement system.
authors.affiliation: Institut für Medizinische Mikrobiologie und Hygiene, Elfriede-Aulhorn-Str. 6, 72076 Tübingen, Germany.
authors.forename: Melanie
authors.initials: M
authors.lastname: Mühlenkamp
authors.affiliation: Institut für Medizinische Mikrobiologie und Hygiene, Elfriede-Aulhorn-Str. 6, 72076 Tübingen, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Oberhettinger
authors.affiliation: University of Oslo, Department of Biosciences, Section for Genetics and Evolutionary Biology, Postboks 1066, Blindern, 0316 Oslo, Norway.
authors.forename: Jack C
authors.initials: JC
authors.lastname: Leo
authors.affiliation: University of Oslo, Department of Biosciences, Section for Genetics and Evolutionary Biology, Postboks 1066, Blindern, 0316 Oslo, Norway.
authors.forename: Dirk
authors.initials: D
authors.lastname: Linke
authors.affiliation: Institut für Medizinische Mikrobiologie und Hygiene, Elfriede-Aulhorn-Str. 6, 72076 Tübingen, Germany. Electronic address: monika.schuetz@med.uni-tuebingen.de.
authors.forename: Monika S
authors.initials: MS
authors.lastname: Schütz
mesh_terms: D018829:Adhesins, Bacterial / Q000378:metabolism*; D000818:Animals; D001422:Bacterial Adhesion; D058947:Bacterial Secretion Systems; D054884:Host-Pathogen Interactions; D006801:Humans; D057131:Immune Evasion; D014774:Virulence; D037521:Virulence Factors / Q000378:metabolism*; D015008:Yersinia enterocolitica / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D015011:Yersinia pseudotuberculosis / Q000378:metabolism / Q000502:physiology*
chemical_list: D018829:Adhesins, Bacterial; D058947:Bacterial Secretion Systems; D037521:Virulence Factors; C064832:YadA protein, Yersinia
keywords: Adhesin; Complement system; Trimeric autotransporter; YadA; Yersinia enterocolitica