Phage_holin_6_2 is a family of holins classified as 1.E.20 in the TC database. The hol gene (PRF9) product (117 aas) of Pseudomonas aeruginosa PAO1 exhibits a hydrophobicity profile similar to holins of P2 and phiCTX phages with two peaks of hydrophobicity that might correspond to either one or two TMSs. Hol functions in conjunction with the lytic enzyme, Lys, a glycosyl hydrolase that breaks-up the murein in the bacterial cell-wall, causing lysis of the cell and hence entry of phage particles [1]. Several members are annotated as pyocin R2_PP when encoded on the chromosome.

1: The R-type pyocin of Pseudomonas aeruginosa is related to P2 phage, and the F-type is related to lambda phage. Nakayama K, Takashima K, Ishihara H, Shinomiya T, Kageyama M, Kanaya S, Ohnishi M, Murata T, Mori H, Hayashi T; Mol Microbiol. 2000;38:213-231. PMID:11069649