Key directions of fundamental research on bacteriophage Receptor Binding Proteins with applied potential.

Over the past decade, interest in research on bacteriophage Receptor Binding Proteins (RBPs) of tailed bacteriophages has increased substantially, reflecting a broader resurgence in phage research. Once underestimated, RBPs have now become the focus of extensive investigation, largely due to their promising applications in pathogen diagnostics, host-range engineering for improved phage therapy, and the development of tailocins, protein-based antibacterial agents capable of inhibiting or eliminating bacterial cells. This review aims to synthesize current knowledge on RBPs function and applications, with particular emphasis on their translational potential. We systematically analyzed recent literature, focusing on structural, biochemical, and functional studies that elucidate mechanisms of host recognition and explore emerging biotechnological and therapeutic uses. The reviewed studies highlight significant advances in understanding RBPs specificity, modular architecture, and adaptability. These features enable targeted bacterial recognition and manipulation of host range. Furthermore, we demonstrate that RBPs can be effectively engineered to be repurposed for diagnostic and antimicrobial applications. Together, these findings position RBPs as a foundational platform for next-generation phage-based technologies and their translation into clinical and industrial applications.