PhiU53 holin family
The Firmicute Phage 'φU53 Holin Family' consists of putative holins that range in size from 117 to 124 amino acyl residues in length and exhibit 3 transmembrane segments found in Bacillota phage. While annotated as holins, it appears as though many members of the φU53 holin family are not yet functionally characterized. A representative list of homologues can be found in the Transporter Classification Database.