The putative holin-like toxin (Hol-Tox) family (TC# 1.E.42) consists of many small proteins, between 34 and 48 amino acyl residues (aas) with a single transmembrane segment (TMSs). Rajesh et al. (2011) first identified the gene and designated it tmp1, which coded for a 34 amino acyl peptide that acts as an antibacterial agent on gram-positive bacteria.[1] This peptide exhibits a single transmembrane domain (TMD) that is believed to play a role in facilitating the antibacterial activity.[1] A representative list of proteins belonging to the Hol-Tox family can be found in the Transporter Classification Database.[2]
Wang, I. N.; Smith, D. L.; Young, R. (2000). "Holins: the protein clocks of bacteriophage infections". Annual Review of Microbiology. 54: 799–825. doi:10.1146/annurev.micro.54.1.799. PMID11018145.