Title
Structure-Functional Characteristics of the Svx Protein—The Virulence Factor of the Phytopathogenic Bacterium Pectobacterium atrosepticum
Author
Natalia Tendiuk, Tatiana Konnova, Olga Petrova, Elena Osipova, Timur Mukhametzyanov, Olga Makshakova, and Vladimir Gorshkov
Year
2022
Journal
Int. J. Mol. Sci. 2022, 23, 6914.
Abstract
The Svx proteins are virulence factors of phytopathogenic bacteria of the Pectobacterium
genus. The specific functions of these proteins are unknown. Here we show that most of the
phytopathogenic species of Pectobacterium, Dickeya, and Xanthomonas 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 Pectobacterium atrosepticum (Pba)—an
extracellular virulence factor secreted into the host plant cell wall (PCW). Using in silico analyses
and by obtaining and analyzing the recombinant Pba Svx and its mutant forms, we showed that
this protein was a gluzincin metallopeptidase. The 3D structure model of the Pba Svx was built and
benchmarked against the experimental overall secondary structure content. Structure-based substrate
specificity analysis using molecular docking revealed that the Pba Svx substrate-binding pocket might
accept -glycosylated proteins represented in the PCW by extensins—proteins that strengthen the
PCW. Thus, these results elucidate the way in which the Pba Svx may contribute to the Pba virulence.
Full Article
Instrument
J-1500 Spectro-polarimeter
Keywords
Gluzincin extracellular metallopeptidases; Molecular docking; Pectobacterium; Plant-pathogen interactions; Protein structure; Svx proteins; Virulence factors