Structural and Functional Interferences from a Molecular Structural Model of Xenocin Toxin from Xenorhabdus nematophila

Bacteriocins constitute the most abundant and diverse family of microbial defense systems. They are produced and secreted to inhibit the growth of closely related, competing bacterial species inhabiting a common ecological niche. One such bacteriocin designated as xenocin, is produced by entomopathogenic bacterium Xenorhabdus nematophila. In our earlier study, we have shown its regulation under SOS conditions and its activity against wide range of bacteria isolated from the gut of insect. In this study three dimensional structure of xenocin has been deciphered with the assistance of automated homology modelling and verified by VERIFY-3D program as well as Ramachandran plot 2.0. Three domain organisation; Translocation (T), Receptor (R) and Catalytic domain (C) has been observed and their structures were studied by CHIMERA software (UCSF). Protein disorder structure and Average Area Buried Upon folding (AABUF) in first 100 amino acid residues of Translocation domain is determined by Globplot and ProtScale software respectively. Conserved amino acid residues in the putative active site of the catalytic domain of xenocin have been deciphered with multiple sequence alignment.