This family of holins is found in several staphylococcal and streptococcal bacteriophages. Holins are a diverse family of proteins that cause bacterial membrane lysis during late-protein synthesis. It is thought that the temporal precision of holin-mediated lysis may occur through the buildup of a holin oligomer which causes the lysis [1].

1: Holins kill without warning. Grundling A, Manson MD, Young R; Proc Natl Acad Sci U S A 2001;98:9348-9352. PMID:11459934