THE PESTICIN RECEPTOR OF YERSINIA-ENTEROCOLITICA - A NOVEL VIRULENCE FACTOR WITH DUAL FUNCTION

Citation
A. Rakin et al., THE PESTICIN RECEPTOR OF YERSINIA-ENTEROCOLITICA - A NOVEL VIRULENCE FACTOR WITH DUAL FUNCTION, Molecular microbiology, 13(2), 1994, pp. 253-263
Citations number
57
Categorie Soggetti
Biology,Microbiology
Journal title
ISSN journal
0950382X
Volume
13
Issue
2
Year of publication
1994
Pages
253 - 263
Database
ISI
SICI code
0950-382X(1994)13:2<253:TPROY->2.0.ZU;2-#
Abstract
The iron-repressible outer membrane protein FyuA of Yersinia enterocol itica operates as a receptor with dual function: (i) as a receptor for the Y. pestis bacteriocin pesticin, and (ii) as a receptor for yersin labactin, a siderophore that is produced by mouse-virulent Y. enteroco litica strains of biogroup IB. Cloning of the FyuA-encoding gene was a chieved by mobilization of a genomic cosmid library of the pesticin-se nsitive and mouse-virulent Y. enterocolitica 0:8 strain WA into the pe sticin-resistant WA fyuA mutant and subsequent in vivo selection of tr ansconjugants for the ability to survive and multiply in mice (phenoty pe mouse virulence). The reisolated transconjugants which survived in mice for 3 d harboured a unique cosmid and phenotypically were pestici n sensitive. From this cosmid a 2650 bp Sall-Pstl fragment conferring pesticin sensitivity was subcloned. Sequencing of this DNA fragment re vealed a single open reading frame of 2022 bp, which encodes a deduced polypeptide of 673 amino acids with a predicted molecular mass of 736 77 Da. Cleavage of a putative signal sequence composed of 22 amino aci ds should lead to a mature protein of 651 amino acids with a molecular mass of 71 368 Da. The open reading frame is preceded by a sequence w hich shares homology with the postulated consensus Fur iron-repressor protein-binding site. FyuA shows homology to other iron-regulated TonB -dependent outer membrane proteins with receptor functions (e.g. BtuB, CirA, FepA, lutA, FhuA, FoxA, FcuA). On the basis of multiple alignme nt of amino acid sequences of FyuA and other TonB-dependent receptors, a phylogenetic tree was constructed, demonstrating that FyuA probably belongs to the citrate subfamily or represents a new subfamily of Ton e-dependent receptors. Moreover, by complementation of the WA fyuA mut ant by the cloned fyuA gene, yersiniabactin uptake and mouse virulence were restored. These studies demonstrate that the cloned pesticin/yer siniabactin receptor FyuA of Y. enterocolitica has the typical feature s of iron-regulated TonB-dependent outer membrane receptors for sidero phores and bacteriocins and is required for mouse virulence.