The Two Partner Secretion Transporters of Yersinia pestis: Cloning, Immunogenicity and In Vivo Expression Following Airway Infection

A bioinformatic screen of Yersinia pestis genome identified 11 TPS components, carrying the POlypeptide TRansport-Associated (POTRA ) domain, found in other pathogens to be involved in immunogenicity and pathogenicity. All rTpsBs (transporters ) cloned and expressed in Escherichia coli induced a humoral responses in immunized mice. Mice surviving intranasal infection with fully virulent Y. pestis Kimberley53 strain generated sera cross reacting with some recombinants TpsBs. Moreover, at least 3 TpsB polypeptides were directly detected in bacteria isolated following intranasal Y. pestis infection. All in vivo produced TpsBs appear to be truncated, missing about 75–85 amino acids. MALDI-TOF-MS analysis permitted to identify the truncation at a region overlapping a domain of a closely related Bordetella pertussis TpsB (FhaC ), recently proposed to undergo a major conformational change that allows effector translocation.