Non-CRISPR phage survival in Streptococcus thermophilus DGCC7710

Streptococcus thermophilus is a model organism for the study of CRISPR-Cas immunity against lytic phages. In addition to CRISPR-Cas, this organism has other mechanisms to survive or evade phage infection. In this study we identified ftsH, a gene encoding a cell wall anchored ATP-dependent protease, as an important regulator of phage attachment. Mutations in ftsH protected against phage infection. In turn, mutations in phage tail proteins allowed them to re-establish infection.