Dressed to kill: How decoration proteins customise the phage capsid

Bacteriophages, the natural predators of bacteria, are being harnessed as a promising alternative to antibiotics against drug-resistant infections as well as other biotechnological applications. Using specific reconstruction algorithms, we resolved high-resolution structures of capsids, necks, and tails across siphophages, podophages, and myophages.

In this talk we will look at decoration proteins, auxiliary components binding the capsid exterior after maturation, occupyingposition-specific asymmetric interfaces even within a single symmetric capsid. We will further describe insertions within the major capsid protein that diversify inter-capsomer contacts, and gene-duplicated proteins that adopt similar folds but occupy divergent structural roles. Together, these findings show that the HK97 fold acts as a conserved architecture onto which decoration and insertion modules are freely added, providing a structural basis for phage diversification and host adaptation. These insights could inform structure-guided phage therapy and capsid engineering.