(A) P2 Y has lytic properties of a holin. Inductions: pKT1-Yam, with CHCl3 added at 65 min (□); pKT1-Yam, with cyanide added at 20 min and CHCl3 at 65 min (■); pKT1-Y, with CHCl3 added at 20 min (▲); pKT1-Y, with cyanide added at 20 min (●); pY (○). (B) Inducible lethality of P2 Y. Inductions: pKT2-Y (○); pKT2-Y, with 2,4-dinitrophenol (DNP) added at −60 min (●); pKT2-Y, with potassium cyanide (KCN) added at −60 min (◆); pKT2-Yam (□); pKT2-Yam, with DNP added at −60 min (■); pKT2-Yam, with KCN added at −60 min (▼). (C) Lysis phenotypes of P2 Y mutants. Inductions: pKT1-Y (▲), pKT1-YL9Q (×), pKT1-YL17P (○), pKT1-YK22M (△), pKT1-YA25V (+), pKT1-YS46C (●), pKT1-YA49T (♢), pKT1-YL53M (◆), pKT1-YC65G (■), pKT1-YM70I (▼), pKT1-YA74T (◣), and pKT1-YG75S (▽).