A novel FK-506-binding-like protein that lacks peptidyl-prolyl isomerase activity is involved in intracellular infection and in vivo virulence of Burkholderia pseudomallei

作者：Norville Isobel H; Breitbach Katrin; Eske Pogodda Kristin; Harmer Nicholas J; Sarkar Tyson Mitali; Titball Richard W; Steinmetz Ivo^*

来源：Microbiology-SGM, 2011, 157(9): 2629-2638.

DOI：10.1099/mic.0.049163-0

Burkholderia pseudomallei is a facultative intracellular bacterial pathogen causing melioidosis, an often fatal infectious disease that is endemic in several tropical and subtropical areas around the world. We previously described a Ptk2 cell-based plague assay screening system of B. pseudomallei transposon mutants that led to the identification of several novel virulence determinants. Using this approach we identified a mutant with reduced plaque formation in which the BPSL0918 gene was disrupted. BPSL0918 encodes a putative FK-506-binding protein (FKBP) representing a family of proteins that typically possess peptidyl-prolyl isomerase (PPlase) activity. A B. pseudomallei Delta BPSL0918 mutant showed a severely impaired ability to resist intracellular killing and to replicate within primary macrophages. Complementation of the mutant fully restored its ability to grow intracellularly. Moreover, B. pseudomallei Delta BPSL0918 was significantly attenuated in a murine model of infection. Structural modelling confirmed a modified FKBP fold of the BPSL0918-encoded protein but unlike virulence-associated FKBPs from other pathogenic bacteria, recombinant BPSL0918 protein did not possess PPlase activity in vitro. In accordance with this observation BPSL0918 exhibits several mutations in residues that have been proposed to mediate PPlase activity in other FKBPs. To our knowledge this B. pseudomallei FKBP represents the first example of this protein family which lacks PPlase activity but is important in intracellular infection of a bacterial pathogen.

• 出版日期2011-9
• 单位河北医科大学