1.E.21 The Listeria Phage A118 Holin (Hol118) Family

Listeria monocytogenes bacteriophage A118 encodes a native holin, hol118, of 93 aas exhibiting 3 putative TMS. When cloned into lambda (λΔSthf) devoid of the S holin, it caused very late cell lysis, beginning 80 min. after induction (Vukov et al., 2003). Hol118 appeared in the cytoplasmic membrane shortly after infection. A second translational start codon (AUG-3) at nucleotide position 40 in the gene gives rise to a second gene product of 83 aas lacking TMS1 (Hol118(83)). It is produced with the full length protein, appears in the membrane, cannot support lambda lysis, and inhibits lysis by Hol118. This dominant inhibitor presumably determines the time of lysis (Vukov et al., 2003). A homologue is found in L. innocua.

The reaction probably catalyzed is:

small molecules + autolysin (in) → small molecules + autolysin (out)


This family belongs to the Holin V Superfamily .
 

References:

Kuo, C.Y., S. Sinha, J.A. Jazayeri, and C.W. Pouton. (2009). A stably engineered, suicidal strain of listeria monocytogenes delivers protein and/or DNA to fully differentiated intestinal epithelial monolayers. Mol Pharm 6: 1052-1061.
Vukov, N., I. Moll, U. Bläsi, S. Scherer, and M.J. Loessner. (2003). Functional regulation of the Listeria monocytogenes bacteriophage A118 holin by an intragenic inhibitor lacking the first transmembrane domain. Mol. Microbiol. 48: 173-186.
Examples:

TC#NameOrganismal TypeExample
1.E.21.1.1

Putative holin

Chloroflexi

Putative holin of Dehalococcoides sp GT

 
1.E.21.1.2

Uncharacterized protein

Firmicutes

Uncharacterized protein of Facklamia hominis

 
1.E.21.1.3

Holin

Enterococcal phage

Holin of Entereococcal phage BC-611

 
1.E.21.1.4

Putative holin of 88 aas and 3 TMSs

Firmicutes

Putative holin of Lysinibacillus fusiformi

 
Examples:

TC#NameOrganismal TypeExample
1.E.21.2.1

Holin, hol118 of 96 aas and 3 TMSs (Kuo et al. 2009).  A stably engineered holin-expressing suicidal attenuated strain of Listeria monocytogenes has been used to deliver proteins and DNA to mammalian intestinal epithelial cells (Kuo et al. 2009).

Firmicute phage

hol118 of Listeria monocytogenes phage A118

 
1.E.21.2.2

Putative holin

Actinobacteria

Putative holin of Bifidobacterium dentium