This family consists of several Listeria bacteriophage holin proteins and related bacterial sequences. 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 build up 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

2: Heterogeneous endolysins in Listeria monocytogenes bacteriophages: a new class of enzymes and evidence for conserved holin genes within the siphoviral lysis cassettes. Loessner MJ, Wendlinger G, Scherer S; Mol Microbiol 1995;16:1231-1241. PMID:8577256