1.E.27 The BhlA Holin (BhlA Holin) Family
A 71 aa BhlA bacteriocin-related holin-like peptide with 1 N-terminal TMS is encoded upstream of a gene encoding an 86 aa holin-like peptide, XhlB in the genome of Bacillus pumilus strain WAPB4 (Aunpad and Panbangred 2012). XhlB is composed of two putative transmembrane domains separated by a β-turn and numerous charged residues in the C-terminus. Dual start motifs were found in both BhlA and XhlB. To analyze the effect of BhlA on bacteria cells, its ORF was cloned and expressed in Escherichia coli. Expression of BhlA was toxic, and the site of action was in the cell membrane, causing death by membrane disruption as demonstrated by transmission electron microscopy (Aunpad and Panbangred 2012).
holin BhlA (70 aas). A member of the DUF2762 family. Its holin function has been demonstrated (Aunpad and Panbangred 2012).
BhlA of Bacillus pumilus
Bacillus subtilis phage SP beta-holin-like protein (70 aas).
Phage SP beta-holin
Phage-like protein (80 aas).
Phage-like protein of Clostridium botulinum
Holin protein BhlA (Anthony et al. 2010).
BhlA of Bacillus licheniformis
Bacteriocin UviB of 64 aas. This protein is in the DUF2762 Superfamily.
UviB of Clostridium perfringens
Uncharacterized protein of 76 aas
UP of Bacillus cereus
Uncharacterized protein of 78 aas
UP of Bacillus thuringiensis