Deletion of amino acids 29 to 81 in adhesion protein YadA of Yersinia enterocolitica serotype O:8 results in selective abrogation of adherence to neutrophils.

In order to analyze the multiple functions of the yersinia adhesin YadA in more detail, we constructed an N-terminally truncated YadA protein (deletion of amino acids [aa] 29 to 81) of Yersinia enterocolitica serotype 0:8. The region aa 29 to 81 of YadA is located between the signal sequence and the amino-terminal hydrophobic domain (aa 80 to 101), which is involved in surface polymerization and collagen binding. The deletion of aa 29 to 81 (resulting in YadADelta29-81) had no effect on the well-known features of YadA such as autoagglutination, serum resistance, HEp-2 cell adherence, binding of collagen, and binding of the complement-inhibiting factor H. In contrast to this, mutant WA(pYVO8-A-Delta29-81), producing the truncated YadADelta29-81 had lost the ability to adhere to polymorphonuclear leukocytes and to induce an oxidative burst. This functional deficiency was comparable to that of a yadA-null mutant (K. Ruckdeschel, A. Roggenkamp, S. Schubert, and J. Heesemann, Infect. Immun. 64:724-733, 1996). Moreover, mutant WA(pYVO8-ADelta29-81) turned out to be attenuated in virulence comparably to the yadA-null mutant, as demonstrated with orogastrically and intravenously infected mice. In summary, this study shows that specific functions of YadA (i) can be impaired by designed mutations and (ii) are important in distinct stages of the infection process.