Cytolethal distending toxin

Cytolethal distending toxin A/C family
crystal structure of the haemophilus ducreyi cytolethal distending toxin
Identifiers
Symbol	CDtoxinA
Pfam	PF03498
Pfam clan	CL0066
InterPro	IPR003558
Available protein structures: Pfam structures PDB RCSB PDB; PDBe PDBsum structure summary

In molecular biology, cytolethal distending toxin (cdt) is a toxin produced by Proteobacteria, including Escherichia coli, Haemophilus spp and Campylobacter spp.This toxin causes distension in certain cell lines,^[1][2] which eventually disintegrate and die. It consists of three subunits: A, B and C. Their sizes are approx. 27.7, 29.5 and 19.9kDa respectively,^[1] and they appear to be entirely novel.^[2] Further research on the complete toxin has revealed that it blocks the cell cycle at stage G2, through inactivation of the cyclin-dependent kinase Cdk1, and without induction of DNA breaks. This leads to multipolar abortive mitosis and micronucleation, associated with centrosomal amplification.^[3] The roles of each subunit are unclear, but it is believed that they have separate roles in pathogenicity.

References

1. ^ ^{a b} Pickett CL, Cottle DL, Pesci EC, Bikah G (March 1994). "Cloning, sequencing, and expression of the Escherichia coli cytolethal distending toxin genes". Infect. Immun. 62 (3): 1046–51. PMC 186222. PMID 8112838. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=186222. 
2. ^ ^{a b} Eyigor A, Dawson KA, Langlois BE, Pickett CL (May 1999). "Cytolethal distending toxin genes in Campylobacter jejuni and Campylobacter coli isolates: detection and analysis by PCR". J. Clin. Microbiol. 37 (5): 1646–50. PMC 84865. PMID 10203548. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=84865. 
3. ^ De Rycke J, Sert V, Comayras C, Tasca C (March 2000). "Sequence of lethal events in HeLa cells exposed to the G2 blocking cytolethal distending toxin". Eur. J. Cell Biol. 79 (3): 192–201. PMID 10777111. 

This article includes text from the public domain Pfam and InterPro IPR003558