Cytotoxic necrotising factor family

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PDB 1hzg EBI.jpg
crystal structure of the inactive c866s mutant of the catalytic domain of e. coli cytotoxic necrotizing factor 1
Symbol CNF1
Pfam PF05785
InterPro IPR008430
SCOP 1hzg

In molecular biology, the cytotoxic necrotising factor family of proteins includes bacterial cytotoxic necrotising factor proteins and the related dermonecrotic toxin (DNT) from Bordetella species. Cytotoxic necrotizing factor 1 (CNF1) is a toxin whose structure from Escherichia coli revealed a 4-layer alpha/beta/beta/alpha structure containing mixed beta-sheets.[1] CNF1 is expressed in strains of E. coli causing uropathogenic and neonatal meningitis. CNF1 alters host cell actin cytoskeleton and promotes bacterial invasion of the blood–brain barrier endothelial cells.[2] CNF1 belongs to a unique group of large cytotoxins that cause constitutive activation of Rho guanosine triphosphatases (GTPases), which are key regulators of the actin cytoskeleton .

Bordetella dermonecrotic toxin (DNT) stimulates the assembly of actin stress fibres and focal adhesions by deamidating or polyaminating Gln63 of the small GTPase Rho. DNT is an A-B toxin composed of an N-terminal receptor-binding (B) domain and a C-terminal enzymatically active (A) domain.[3]


  1. ^ Buetow L, Flatau G, Chiu K, Boquet P, Ghosh P (July 2001). "Structure of the Rho-activating domain of Escherichia coli cytotoxic necrotizing factor 1". Nat. Struct. Biol. 8 (7): 584–8. doi:10.1038/89610. PMID 11427886. 
  2. ^ Landraud L, Gibert M, Popoff MR, Boquet P, Gauthier M (March 2003). "Expression of cnf1 by Escherichia coli J96 involves a large upstream DNA region including the hlyCABD operon, and is regulated by the RfaH protein". Mol. Microbiol. 47 (6): 1653–67. doi:10.1046/j.1365-2958.2003.03391.x. PMID 12622819. 
  3. ^ Matsuzawa T, Kashimoto T, Katahira J, Horiguchi Y (July 2002). "Identification of a receptor-binding domain of Bordetella dermonecrotic toxin". Infect. Immun. 70 (7): 3427–32. doi:10.1128/iai.70.7.3427-3432.2002. PMC 128056. PMID 12065482. 

This article incorporates text from the public domain Pfam and InterPro IPR008430