title: Protein Domain Analysis of C. botulinum Type A Neurotoxin and Its Relationship with Other Botulinum Serotypes.
abstract: Botulinum neurotoxins (BoNTs) are highly potent poisons produced by seven serotypes of Clostridium botulinum. The mechanism of neurotoxin action is a multistep process which leads to the cleavage of one of three different SNARE proteins essential for synaptic vesicle fusion and transmission of the nerve signals to muscles: synaptobrevin, syntaxin, or SNAP-25. In order to understand the precise mechanism of neurotoxin in a host, the domain structure of the neurotoxin was analyzed among different serotypes of C. botulinum. The results indicate that neurotoxins type A, C, D, E and F contain a coiled-coil domain while types B and type G neurotoxin do not. Interestingly, phylogenetic analysis based on neurotoxin sequences has further confirmed that serotypes B and G are closely related. These results suggest that neurotoxin has multi-domain structure, and coiled-coil domain plays an important role in oligomerisation of the neurotoxin. Domain analysis may help to identify effective antibodies to treat Botulinum toxin intoxication.
authors: Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740, USA. shashi.sharma@fda.hhs.gov
authors: Shashi K
authors: SK
authors: Sharma
authors: Uma
authors: U
authors: Basavanna
authors: Hem D
authors: HD
authors: Shukla
mesh_terms: D001905:Botulinum Toxins / Q000235:genetics; D019274:Botulinum Toxins, Type A / Q000378:metabolism; D003014:Clostridium botulinum / Q000378:metabolism; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D065288:Serogroup; D050825:Synaptosomal-Associated Protein 25 / Q000378:metabolism
chemical_list: D050825:Synaptosomal-Associated Protein 25; D001905:Botulinum Toxins; D019274:Botulinum Toxins, Type A