*1.E.55 The Brachyspira* holin (B-Hol) Family** VSH-1 is a mitomycin C-inducible prophage of the anaerobic spirochete, Brachyspira hyodysenteriae. Purified VSH-1 virions are noninfectious, contain random 7.5-kb fragments of the bacterial genome, and mediate generalized transduction of B. hyodysenteriae cells, showing that they represent a Gene Transfer Agent (GTA) (Matson et al. 2005). VSH-1 genes spanned 16.3 kb of the B. hyodysenteriae chromosome and were flanked by bacterial genes. VSH-1 identified genes and unidentified, intervening open reading frames, were consecutively organized in head (seven genes), tail (seven genes), and lysis (four genes) clusters in the same transcriptional direction. Putative lysis genes encoding endolysin (Lys) and holin proteins were identified from sequence and structural similarities of their translated protein products with GenBank bacteriophage proteins. Recombinant Lys protein hydrolyzed peptidoglycan purified from B. hyodysenteriae cells. The identified VSH-1 genes exceed the DNA capacity of VSH-1 virions and do not encode traditional bacteriophage early functions involved in DNA replication. These genome properties explain the noninfectious nature of VSH-1 virions and confirm its resemblance to known prophage-like, GTAs of other bacterial species, such as the GTA from Rhodobacter capsulatus.
References:
Matson, E.G., M.G. Thompson, S.B. Humphrey, R.L. Zuerner, and T.B. Stanton. (2005). Identification of genes of VSH-1, a prophage-like gene transfer agent of Brachyspira hyodysenteriae. J. Bacteriol. 187: 5885-5892.
Examples:
TC#	Name	Organismal Type	Example
1.E.55.1.1	*GTA holin of 85 aas and 2 TMSs (Matson et al.* 2005).**	Spirochaetae	GTA holin of Brachyspira hyodysenteriae

1.E.55.1.2	VSH-1 holin of 92 aas and 2 TMSs.	Spirochaetae	Holin of Brachyspira pilosicoli

1.E.55.1.3	Putative holin of 97 aas and 2 TMSs.	Spirochaetae	Putative holin of Brachyspira (Serpulina) intermedia

1.E.55.1.4	Putative holin of 92 aas and 2 TMSs	Spirochaetae	Putative holin of Brachyspira pilosicoli

Examples:
TC#	Name	Organismal Type	Example
1.E.55.2.1	Putative holin of 142 aas and 3 TMSs	Proteobacteria	Putative holin of Pseudomonas syringae

1.E.55.2.2	Putative porin of 143 aas and 3 TMSs	Proteobacteria	Putative porin of Pseudomonas putida

1.E.55.2.3	Putative holin of 133 aas and 3 TMSs	Proteobacteria	Putative holin of Photorhabdus temperata

1.E.55.2.4	Putative holin of 126 aas and 2 TMSs	Proteobacteria	Putative holin of E. coli

1.E.55.2.5	Putative holin of 143 aas and 3 TMSs	Actinobacteria	Putative holin of Mycobacterium abscessus

Examples:
TC#	Name	Organismal Type	Example
1.E.55.3.1	Putative holin of 105 aas and 4 TMSs	Firmicutes	Putative holin of Staphylococcus pasteuri

1.E.55.3.2	Uncharacterized protein of 105 aas and 4 TMSs	Firmicutes	UP of Macrococcus caseolyticus