Identifying a potential receptor for the antibacterial peptide of sponge Axinella donnani endosymbiont

• The receptor protein of the peptide was identified by comparative genomics approach
• The active site identification was performed for the functional regions of BamA
• The 3D structure of the novel peptide was modeled using de novo modeling
• The BamA protein was docked with the peptide structure using Schrodinger software
• MD simulations performed for the stability of the peptide and its complex with BamA

Marine sponges and their associated bacteria are rich sources of novel secondary metabolites with therapeutic usefulness. In our earlier work, we have identified a novel antibacterial peptide from the marine sponge Axinella donnani endosymbiotic bacteria. In this work, we have carried out a comparative genomic analysis and identified a set of 60 proteins as probable receptor which is common in all the strains. The analysis on binding substrate showed that β barrel assembly machinery (BamA) of the outer membrane protein 85 (omp85) superfamily is a potential receptor protein for the antibacterial peptide. It plays a central role in OMP biogenesis, especially in cell viability. Further, the triplet and quartet motifs RGF and YGDG, respectively in L6 loop are conserved over all the strains and these conserved residues interact with antibacterial peptide to inhibit the BamA function, which is essential for OMP biogenesis.