The ''Clostridium difficile'' TcdE Holin (TcdE Holin) Family
TC# 1.E.19
is a group of transporters belonging to the

Holin Superfamily IV The Holin superfamily IV is a superfamily of integral membrane transport proteins. It is one of the seven different holin superfamilies in total. The Holin superfamily IV includes the TC families: 1.E.10- The ''Bacillus subtilis'' φ29 Holin (φ ...

. A representative list of its members can be found in th
Transporter Classification Database
Toxigenic strains of ''

C. difficile ''Clostridioides difficile'' ( syn. ''Clostridium difficile'') is a bacterium that is well known for causing serious diarrheal infections, and may also cause colon cancer. Also known as ''C. difficile'', or ''C. diff'' (), is Gram-positive spe ...

'' produce two large toxins (TcdA and TcdB) encoded within a pathogenicity locus. ''tcdE,'' encoded between ''tcdA'' and ''tcdB,'' encodes a 166 amino acyl (aa) protein which causes

death Death is the irreversible cessation of all biological functions that sustain an organism. For organisms with a brain, death can also be defined as the irreversible cessation of functioning of the whole brain, including brainstem, and brain ...

to ''

E. coli ''Escherichia coli'' (),Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. also known as ''E. coli'' (), is a Gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus ''Escher ...

'' when expressed, and the structure of TcdE resembles holins. TcdE acts on the bacterial membrane. Since TcdA and TcdB lack signal peptides, they may be released via TcdE either prior to or subsequent to cell lysis. Other Clostridial species bear homologues of TcdE. The transport reaction believed to be catalyzed by TcdE is:

Toxin (in) → Toxin (out)

References

Holins Protein families {{Membrane-protein-stub

See also

Further reading

References