Subtractive genome mining in Xanthomonas citri pv. citri strain 306 for identifying novel drug target proteins coupled with in-depth protein-protein interaction and coevolution analysis - A leap towards prospective drug design.

Citrus canker poses a serious threat to a highly significant citrus fruit crop, this disease caused by one of the most destructive bacterial plant pathogens Xanthomonas citri pv. citri (Xcc). Bacterial plant diseases significantly reduce crop yields worldwide, making it more difficult to supply the growing food demand. The high levels of antibiotic resistance in Xcc strains are diminishing the efficacy of current control measures, necessitating the exploration of novel therapeutic targets to address the escalating antimicrobial resistance trend. Genome subtraction approach along with protein-protein network and coevolution analysis were used to identify potential drug targets in Xcc stain 306. The study involved retrieving the Xcc proteome from the UniProt database, eliminating paralogous proteins using CD-HIT (80 % identity cutoff), and selecting nonhomologous proteins through BLASTp (e-value <0.005). Essential proteins were identified using BLAST against the DEG (e-value cutoff 0.00001). 750 essential proteins were identified that are nonhomologous to citrus plant. Subsequent analyses included metabolic pathway assessment, subcellular localization prediction, and druggability analysis. Protein network analysis, coevolution analysis, protein active site identification was also performed. In conclusion, this study identified eight potential drug targets (GlmU, CheA, RmlD, GspE, FleQ, RpoN, Shk, SecB), highlighting RpoN, FleQ, and SecB as unprecedented targets for Xcc. These findings may contribute to the development of novel antimicrobial agents in the future that can efficiently control citrus canker disease.