Secretome analyses of Pectobacterium brasiliense 1692 outer membrane vesicles and the type 6 secretion system

Data for this study determined the secretome associated with outer membrane vesicles (OMVs) and the type 6 secretion system (T6SS) to understand the biology of this strain, including the strategies it uses to succeed within complex communities during the infection of its hosts. OMVs identified using scanning and transmission electron microscopy were tracked in cell-free supernatants using nanoparticle tracking analysis (NTA). The methodology to identify OMV and T6SS-associated proteins entailed computational and proteomics approaches. OMVs and T6SS secrete diverse proteins for multiple predicted roles into the environment and target cells. In addition, some cargoes were predicted using Bastion tools to be shared among secretion systems.  Computational characterisation was carried out to understand Avirulence L (AvrL), a shared substrate between the T2SS, OMVs, and putatively T6SS. Evolutionary analyses revealed that many bacteria encode avrL homologs. Further investigations predicted that AvrL contains two domains and seven intrinsically disordered regions. Regarding interacting partners, AvrL was predicted to be functionally linked to T2SS substrates, further supporting its association with T2SS. A molecular interaction map of the AvrL and screening showed that 19 differentially expressed genes, mainly transcription factors are potential AvrL targets in Solanum tuberosum cv. Valor when infected by Pbr1692.