title: Mechanism of substrate recognition by the novel Botulinum Neurotoxin subtype F5.
abstract: Botulinum Neurotoxins (BoNTs) are the causative agents of botulism, which act by potently inhibiting the neurotransmitter release in motor neurons. Seven serotypes of BoNTs designated as BoNT/A-G have been identified. Recently, two novel types of Botulinum neurotoxins, which cleave a novel scissile bond, L(54)-E(55), of VAMP-2 have been reported including BoNT/F subtype F5 and serotype H. However, little has been known on how these BoNTs recognize their substrates. The present study addressed for the first time the unique substrate recognition mechanism of LC/F5. Our data indicated that the optimal peptide required for efficient LC/F5 substrate cleavage is VAMP-2 (20-65). Interestingly, the overall mode of substrate recognition adopted by LC/F5 was similar to LC/F1, except that its recognition sites were shifted one helix toward the N-terminus of VAMP-2 when compared to that of LC/F1. The composition of LC/F5 pockets were found to have changed accordingly to facilitate specific recognition of these new sites of VAMP-2, including the P2', P1', P2, P3, B3, B2 and B1 sites. The study provides direct evidence of the evolutionary adaption of BoNT to recognize its substrate which is useful for effective antitoxin and inhibitor development.
authors.affiliation: Shenzhen Key lab for Food Biological Safety Control, Food Safety and Technology Research Center, Hong Kong PolyU Shen Zhen Research Institute, Shenzhen, P. R. China.|State Key Lab of Chirosciences, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
authors.forename: Jiubiao
authors.initials: J
authors.lastname: Guo
authors.affiliation: Shenzhen Key lab for Food Biological Safety Control, Food Safety and Technology Research Center, Hong Kong PolyU Shen Zhen Research Institute, Shenzhen, P. R. China.|State Key Lab of Chirosciences, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
authors.forename: Edward Wai Chi
authors.initials: EW
authors.lastname: Chan
authors.affiliation: Shenzhen Key lab for Food Biological Safety Control, Food Safety and Technology Research Center, Hong Kong PolyU Shen Zhen Research Institute, Shenzhen, P. R. China.|State Key Lab of Chirosciences, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
authors.forename: Sheng
authors.initials: S
authors.lastname: Chen
mesh_terms: D019274:Botulinum Toxins, Type A / Q000378:metabolism*; D020134:Catalytic Domain; D002942:Circular Dichroism; D006801:Humans; D006868:Hydrolysis; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D008958:Models, Molecular; D017433:Protein Structure, Secondary; D013379:Substrate Specificity; D050988:Vesicle-Associated Membrane Protein 2 / Q000737:chemistry / Q000378:metabolism*
chemical_list: D050988:Vesicle-Associated Membrane Protein 2; D019274:Botulinum Toxins, Type A