1T3C

Clostridium botulinum type E catalytic domain E212Q mutant

Summary for 1T3C

• Entry DOI: 10.2210/pdb1t3c/pdb
• Related: 1T3A
• Descriptor: neurotoxin type E, ZINC ION, CHLORIDE ION, ... (4 entities in total)
• Functional Keywords: clostridium botulinum, catalytic domain, e212q mutant, light chain, hydrolase, toxin
• Biological source: Clostridium botulinum
• Cellular location: Botulinum neurotoxin E light chain: Secreted. Botulinum neurotoxin E heavy chain: Secreted: Q00496
• Total number of polymer chains: 2
• Total formula weight: 95889.71

Authors

Agarwal, R.,Eswaramoorthy, S.,Kumaran, D.,Binz, T.,Swaminathan, S. (deposition date: 2004-04-26, release date: 2004-06-29, Last modification date: 2023-08-23)

Primary citation

Agarwal, R.,Eswaramoorthy, S.,Kumaran, D.,Binz, T.,Swaminathan, S.
Structural analysis of botulinum neurotoxin type E catalytic domain and its mutant Glu212-->Gln reveals the pivotal role of the Glu212 carboxylate in the catalytic pathway
Biochemistry, 43:6637-6644, 2004

PubMed Abstract: The seven serotypes of botulinum neurotoxins (A-G) produced by Clostridium botulinum share significant sequence homology and structural similarity. The functions of their individual domains and the modes of action are also similar. However, the substrate specificity and the peptide bond cleavage selectivity of their catalytic domains are different. The reason for this unique specificity of botulinum neurotoxins is still baffling. If an inhibitor leading to a therapeutic drug common to all serotypes is to be developed, it is essential to understand the differences in their three-dimensional structures that empower them with this unique characteristic. Accordingly, high-resolution structures of all serotypes are required, and toward achieving this goal the crystal structure of the catalytic domain of C. botulinum neurotoxin type E has been determined to 2.1 A resolution. The crystal structure of the inactive mutant Glu212-->Gln of this protein has also been determined. While the overall conformation is unaltered in the active site, the position of the nucleophilic water changes in the mutant, thereby causing it to lose its ability to activate the catalytic reaction. The structure explains the importance of the nucleophilic water and the charge on Glu212. The structural differences responsible for the loss of activity of the mutant provide a common model for the catalytic pathway of Clostridium neurotoxins since Glu212 is conserved and has a similar role in all serotypes. This or a more nonconservative mutant (e.g., Glu212-->Ala) could provide a novel, genetically modified protein vaccine for botulinum.

PubMed: 15157097
DOI: 10.1021/bi036278w

Experimental method

X-RAY DIFFRACTION (1.9 Å)