4ELC

Crystal structure of the catalytic domain of botulinum neurotoxin BoNT/A C134 mutant with MTSEA modified Cys-165

Summary for 4ELC

• Entry DOI: 10.2210/pdb4elc/pdb
• Related: 2ISE 3BWI 4EJ5 4EL4
• Descriptor: Botulinum neurotoxin A light chain, ZINC ION, IMIDAZOLE, ... (9 entities in total)
• Functional Keywords: metalloprotease, peptidase m27 superfamily, clostridial neurotoxin zinc protease, human target snap-25, hydrolase
• Biological source: Clostridium botulinum
• Cellular location: Botulinum neurotoxin A light chain: Secreted. Botulinum neurotoxin A heavy chain: Secreted: P10845
• Total number of polymer chains: 1
• Total formula weight: 51985.81

Authors

Stura, E.A.,Vera, L.,Ptchelkine, D.,Bakirci, H.,Garcia, S.,Dive, V. (deposition date: 2012-04-10, release date: 2012-08-15, Last modification date: 2023-09-20)

Primary citation

Stura, E.A.,Le Roux, L.,Guitot, K.,Garcia, S.,Bregant, S.,Beau, F.,Vera, L.,Collet, G.,Ptchelkine, D.,Bakirci, H.,Dive, V.
Structural Framework for Covalent Inhibition of Clostridium botulinum Neurotoxin A by Targeting Cys165.
J.Biol.Chem., 287:33607-33614, 2012

PubMed Abstract: Clostridium botulinum neurotoxin type A (BoNT/A) is one of the most potent toxins for humans and a major biothreat agent. Despite intense chemical efforts over the past 10 years to develop inhibitors of its catalytic domain (catBoNT/A), highly potent and selective inhibitors are still lacking. Recently, small inhibitors were reported to covalently modify catBoNT/A by targeting Cys(165), a residue located in the enzyme active site just above the catalytic zinc ion. However, no direct proof of Cys(165) modification was reported, and the poor accessibility of this residue in the x-ray structure of catBoNT/A raises concerns about this proposal. To clarify this issue, the functional role of Cys(165) was first assessed through a combination of site-directed mutagenesis and structural studies. These data suggested that Cys(165) is more involved in enzyme catalysis rather than in structural property. Then by peptide mass fingerprinting and x-ray crystallography, we demonstrated that a small compound containing a sulfonyl group acts as inhibitor of catBoNT/A through covalent modification of Cys(165). The crystal structure of this covalent complex offers a structural framework for developing more potent covalent inhibitors catBoNT/A. Other zinc metalloproteases can be founded in the protein database with a cysteine at a similar location, some expressed by major human pathogens; thus this work should find broader applications for developing covalent inhibitors.

PubMed: 22869371
DOI: 10.1074/jbc.M112.396697

Experimental method

X-RAY DIFFRACTION (1.8 Å)