Structural Features of a Highly Conserved Omp16 Protein of Pasteurella multocida Strains and Comparison with Related Peptidoglycan-associated Lipoproteins (PAL)

Bacterial lipoproteins of varying size and functional role in physiology/pathogenesis are widely prevalent among Gram-negative bacterial species. Among virulent bacteria, Pasteurella multocida is known to be associated with diverse infectious diseases of livestock worldwide and possess several outer membrane proteins (OMPs) as virulence factors. In the present study, we cloned and sequenced omp16 gene of different P. multocida strains (n = 9) of Indian origin and compared with representative related bacterial species from Pasteurellaceae (n = 28) as well as others (n = 11). Phylogenetic and multiple sequence alignment revealed high degree conservation of Omp16 among P. multocida strains. However, it significantly differed from similar peptidoglycans-associated lipoproteins of other Gram-negative bacterial species. Notably, a conversed lipobox at N-terminus of proteins was noticed among all bacterial species. Further, three dimensional homology model of Omp16 was predicted and its structural features were analyzed. The study indicated the potential possibilities to use either native or recombinant Omp16 protein in developing species-specific diagnostic assay or broadly active subunit vaccine along with suitable adjuvant for pasteurellosis in livestock.