| Symbol: | CNF1 |
| 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]