M2 hol family explained

The Mycobacterial 2 TMS Phage Holin (M2 Hol) Family (TC# 1.E.36) is a group of transporters belonging to the Holin Superfamily VII.^[1] The Mycobactrerial 2 transmembrane segment (TMS) Holins have been identified and recognized by Catalao et al (2012).^[2] The Mycobacterium phage D29 gp11 protein (TC# 1.E.36.1.7) is a holin that, upon expression, rapidly kills both E. coli and Mycobacterium smegmatis. Shortening gp11 from its C-terminus resulted in diminished cytotoxicity and smaller holes. The two TMSs at the N-terminus alone do not integrate into the cytoplasmic membrane and do not show toxicity.^[3] Fusion of the two TMSs and a small C-terminal coiled-coil region resulted in restoration of cell killing. The second TMS is dispensable for toxicity. The gp11 C-terminal region is therefore necessary but not sufficient for toxicity.

See also

• Holin
• Lysin
• Transporter Classification Database

Further reading

• Delisle . Allan L. . Barcak . Gerard J. . Guo . Ming . 2006 . Isolation and expression of the lysis genes of Actinomyces naeslundii phage Av-1 . Applied and Environmental Microbiology . 72 . 2. 1110–1117 . 10.1128/AEM.72.2.1110-1117.2006 . 16461656 . 1392916 . 2006ApEnM..72.1110D .
• Lella . Muralikrishna . Mahalakshmi . Radhakrishnan . 2013 . Pro-Gly mediated conformational switch of mycobacteriophage D29 holin transmembrane domain I is lipid concentration driven . Chemical Communications . 49 . 83. 9594–9596 . 10.1039/c3cc45058a . 24018990 .

Notes and References

1. Reddy. Bhaskara L.. Saier Jr.. Milton H.. 2013-11-01. Topological and phylogenetic analyses of bacterial holin families and superfamilies. Biochimica et Biophysica Acta (BBA) - Biomembranes. 1828. 11. 2654–2671. 10.1016/j.bbamem.2013.07.004. 3788059. 23856191.
2. Catalão. Maria João. Gil. Filipa. Moniz-Pereira. José. São-José. Carlos. Pimentel. Madalena. 2013-07-01. Diversity in bacterial lysis systems: bacteriophages show the way. FEMS Microbiology Reviews. 37. 4. 554–571. 10.1111/1574-6976.12006. 1574-6976. 23043507. free.
3. Kamilla. Soumya. Jain. Vikas. 2016-01-01. Mycobacteriophage D29 holin C-terminal region functionally assists in holin aggregation and bacterial cell death. The FEBS Journal. 283. 1. 173–190. 10.1111/febs.13565. 1742-4658. 26471254. 39285978. free.