TAL effectors and the predicted host targets of pomegranate bacterial blight pathogen Xanthomonas citri pv. punicae

In silico prediction of putative antimicrobial targets in Xanthomonas citri pv. punicae using genome subtraction approach

Xanthomonas citri pv. punicae (Xcp) is the causative agent of bacterial blight disease in pomegranate and severely affects its production. The current control strategies for this disease provide inadequate protection. Identifying novel bactericide target proteins in pathogenic bacteria and formulating selective chemicals against those proteins is an effective approach to containing the disease. In this study, we used the genome subtraction approach and identified 595 Xcp proteins that are non-homologous to the pomegranate proteome, of which 69 are found to be essential proteins. These 69 proteins are considered possible drug target proteins in Xcp. Further, these proteins were subjected to subcellular localization, KEGG pathway, and virulent prediction analysis. Our systematic bioinformatics analysis deciphered 33 virulent proteins, of which two are iron complex outer membrane receptors, and the third is a T4SS PilQ protein localized in the outer membrane. These outer membrane-localized proteins are potential candidate targets for antibacterial agents, and the two iron complex outer membrane receptor proteins show homology with the Drug bank listed drug target sequences. From this study, we inferred that PilQ could be considered a novel antimicrobial target of Xcp, and therefore we deciphered the PilQ protein-protein interacting partners and phylogenetic relatedness. We have also predicted the physiochemical properties, secondary, and tertiary structure of PilQ protein which will be helpful in the design of antimicrobials. The identification of Xcp specific targets is the first step towards the development of a chemical control agent that is more selective with minimum environmental impact.