Structure-Functional Characteristics of the Svx Protein-The Virulence Factor of the Phytopathogenic Bacterium .

The Svx proteins are virulence factors of phytopathogenic bacteria of the genus. The specific functions of these proteins are unknown. Here we show that most of the phytopathogenic species of , , and genera have genes encoding Svx proteins, as well as some plant-non-associated species of different bacterial genera. As such, the Svx-like proteins of phytopathogenic species form a distinct clade, pointing to the directed evolution of these proteins to provide effective interactions with plants. To get a better insight into the structure and functions of the Svx proteins, we analyzed the Svx of ()-an extracellular virulence factor secreted into the host plant cell wall (PCW). Using in silico analyses and by obtaining and analyzing the recombinant Svx and its mutant forms, we showed that this protein was a gluzincin metallopeptidase. The 3D structure model of the Svx was built and benchmarked against the experimental overall secondary structure content. Structure-based substrate specificity analysis using molecular docking revealed that the Svx substrate-binding pocket might accept α-glycosylated proteins represented in the PCW by extensins-proteins that strengthen the PCW. Thus, these results elucidate the way in which the Svx may contribute to the virulence.