Novel Receptor Binding Domains Fused to the R2 Pyocin Tail Fiber Kill Target Bacteria

Two tailocins, MobyWanKenobi and John Henry, were engineered to target Stenotrophomonas maltophilia and gram-positive and gram-negative bacteria, respectively. Each engineered tailocin was able to reduce cell abundances of target bacteria, indicating the potential for these tailocins to be used as antimicrobial therapeutics. Tailocins are intact tail structure remnants of defective prophages that can no longer form a capsid. Compared to intact bacteriophages currently being pursued for antimicrobial therapies, tailocins show great therapeutic potential as novel bactericidal particles. Because they do not have genomes, they cannot transfer genes to, or integrate into, genomes of their target bacteria. In addition, tailocins cannot reproduce, and each tailocin can at maximum kill one bacterial cell before it becomes inert, making it feasible to better control dose. The MobyWanKenobi and John Henry tailocins were engineered by fusing the tail spike from myophage Moby or the human Carbohydrate Recognition Domain of Mannose-Binding Lectin, respectively, with the Pseudomonas aeruginosa R2 pyocin tail fiber. This fusion approach, developed by Pylum Biosciences to engineer the Escherichia coli O157:H7-specific tailocin Avidocin, shows great promise for targeted tailocin design.