Serine protease RAYM_01812 (SspA) inhibits complement-mediated killing and monocyte chemotaxis and contributes to virulence of <i>Riemerella anatipestifer</i> in ducks.

ABSTRACT: Riemerella anatipestifer (RA) is a significant poultry pathogen causing acute septicemia and inflammation. The function of protease RAYM_01812, responsible for gelatin degradation, is unexplored in RA pathogenesis. To elucidate its role, we generated a deletion mutant ΔRAYM_01812 (ΔRAYM) and complementary CΔRAYM_01812 (CΔRAYM) strain and revealed the protease's role in extracellular gelatinase activity. By expressing full-length 76 kDa RAYM_01812 protein without signal peptide as well as seven partial structural domains fragments, we evidence that the N-terminal propeptide acts as an enzymatic activity inhibitor and it gets cleaved at A¹¹². Also, we show that the β-fold sheet domain is necessary for enhancing the enzymatic protease activity. Sequential auto-proteolysis fo

SUBMITTER: Yang R 

PROVIDER: S-EPMC11540087 | biostudies-literature | 2024 Dec

REPOSITORIES: biostudies-literature