Identification of a Novel Elastin-Degrading Enzyme from the Fish Pathogen Flavobacterium psychrophilum

Tatiana Rochat (1, 2) , D. Pérez-Pascual (1) , H. Nilsen (3) , M. Carpentier (4) , S. Bridel (1) , J.-F. Bernardet (1) , E. Duchaud (1)

1 VIM (UR 0892) - Unité de recherche Virologie et Immunologie Moléculaires
2 INRAE - Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement
3 Norwegian Veterinary Institute [Oslo]
4 ISYEB - Institut de Systématique, Evolution, Biodiversité

Hydrolytic extracellular enzymes degrading host tissues potentially play a role in bacterial pathogenesis. Flavobacterium psychrophilum is an important bacterial pathogen of salmonid fish reared in freshwater throughout the world. Diversity among isolates has been described at the phenotypic, serological, and genomic levels , but the links between these various traits remain poorly understood. Using a genome-wide association study, we identified a gene encoding a novel elastinolytic enzyme in F. psychrophilum. To formally demonstrate enzymatic activity, this gene (FP0506 from strain JIP 02/86) was expressed in the elastinolysis-deficient strain OSU THCO2-90, resulting in proficient elastin-degrading cells. The encoded protein is predicted to be a cell-surface-exposed lipoprotein with no homology to previously reported elastases. FP0506 might belong to the zincin tribe and gluzincin clan of met-alloproteases, and this new elastase-encoding gene seems to be present only in some members of the family Flavobacteriaceae.

Mots clés: metalloprotease; fish pathogen; Flavobacterium psychrophilum; elastin; elastase; gluzincin

Domaines: Bactériologie; Biochimie [q-bio.BM]

Tatiana Rochat, D. Pérez-Pascual, H. Nilsen, M. Carpentier, S. Bridel, et al.. Identification of a Novel Elastin-Degrading Enzyme from the Fish Pathogen Flavobacterium psychrophilum. Applied and Environmental Microbiology, 2019, 85 (6), pp.e02535-18. ⟨10.1128/AEM.02535-18⟩. ⟨hal-02311311⟩