7K84
Crystal structure of BoNT/E LC-HN domain in complex with VHH JLE-E5
Summary for 7K84
| Entry DOI | 10.2210/pdb7k84/pdb |
| Descriptor | Botulinum neurotoxin type E, JLE-E5, ZINC ION, ... (5 entities in total) |
| Functional Keywords | botulinum neurotoxin (bont), vhh, receptor-binding domain, toxin, antitoxin |
| Biological source | Clostridium botulinum More |
| Total number of polymer chains | 2 |
| Total formula weight | 111151.86 |
| Authors | |
| Primary citation | Lam, K.H.,Perry, K.,Shoemaker, C.B.,Jin, R. Two VHH Antibodies Neutralize Botulinum Neurotoxin E1 by Blocking Its Membrane Translocation in Host Cells. Toxins, 12:-, 2020 Cited by PubMed Abstract: Botulinum neurotoxin serotype E (BoNT/E) is one of the major causes of human botulism, which is a life-threatening disease caused by flaccid paralysis of muscles. After receptor-mediated toxin internalization into motor neurons, the translocation domain (H) of BoNT/E transforms into a protein channel upon vesicle acidification in endosomes and delivers its protease domain (LC) across membrane to enter the neuronal cytosol. It is believed that the rapid onset of BoNT/E intoxication compared to other BoNT serotypes is related to its swift internalization and translocation. We recently identified two neutralizing single-domain camelid antibodies (VHHs) against BoNT/E1 termed JLE-E5 and JLE-E9. Here, we report the crystal structures of these two VHHs bound to the LCH domain of BoNT/E1. The structures reveal that these VHHs recognize two distinct epitopes that are partially overlapping with the putative transmembrane regions on H, and therefore could physically block membrane association of BoNT/E1. This is confirmed by our in vitro studies, which show that these VHHs inhibit the structural change of BoNT/E1 at acidic pH and interfere with BoNT/E1 association with lipid vesicles. Therefore, these two VHHs neutralize BoNT/E1 by preventing the transmembrane delivery of LC. Furthermore, structure-based sequence analyses show that the 3-dimensional epitopes of these two VHHs are largely conserved across many BoNT/E subtypes, suggesting a broad-spectrum protection against the BoNT/E family. In summary, this work improves our understanding of the membrane translocation mechanism of BoNT/E and paves the way for developing VHHs as diagnostics or therapeutics for the treatment of BoNT/E intoxication. PubMed: 32992561DOI: 10.3390/toxins12100616 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.5 Å) |
Structure validation
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