Elucidation of molecular function of phage protein responsible for optimization of host cell lysis

Bacteriophages (or phages) replicate by utilizing bacterial resources and destroy their host cells at the end of the replication cycle. Phages employ multiple proteins to optimize host cell lysis, thereby maximizing the production of phage particles. However, elucidating the entire lysis process is challenging due to the abundance of uncharacterized genes in the phage genome.

In this study, we identified a gene orf52 from BSPM4 phage genome that showed antibacterial activity in Salmonella. Investigation of physiological role of ORF52 in the phage replication revealed that ORF52 could modulate the holin function to fine-tune a cell lysis, providing replication advantages to phages under high phage population density.

We concluded that ORF52 may optimize phage replication by modulating the timing of phage-mediated cell lysis. This study provides a unique example of a phage protein involved in fine-tuning lysis timing.