Structural Features of Clostridium botulinum Neurotoxin Subtype A2 Cell Binding Domain

Gregory, Kyle S.; Mahadeva, Tejaswini B.; Liu, Sai Man; Acharya, K. Ravi

doi:10.3390/toxins14050356

Cited by 5 publications

(21 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For the H C /A6 (crystal form II) structure there is a continuation of electron density between the Nζ of Lys 1236 and Sγ of Cys 1280 residues ( Figure 3 D), whereas in the H C /A6:GD1a structure Cys 1280 forms a disulphide bridge with Cys 1236, and the structure of H C /A6 (crystal form I) shows neither ( Figure 3 , blue). This is consistent with similar observations with H C /A2 and H C /A5 [ 25 , 29 ] and such Lys-O-Cys bridging interactions are believed to be widespread in protein structures but under-reported [ 31 ]. It is likely that these different bridging interactions could lead to multiple conformations that the loop can adopt, however, the biological significance of the Cys-Lys bridge remains unclear at the moment.…”

Section: Resultssupporting

confidence: 92%

“…The program Dyndom [ 30 ] revealed a large hinge rotation of ~16.8° in H C /A6 (crystal form II) when compared to H C /A6 (crystal form I) and H C /A6:GD1a ( Figure 4 ). To date, this is the largest “hinge motion” in subdomain orientation observed among BoNT/A subtype structures [ 25 , 27 ], and it suggests a high degree of flexibility existing between the H CN and H CC subdomains. The biological implication of this hinge-rotation has not yet been determined; however, it has been previously suggested that it may aid in orientating the H N towards the membrane in preparation for translocation [ 23 ].…”

Section: Resultsmentioning

confidence: 99%

“…This was observed previously for H C /A2, H C /A3, and H C /A5. Furthermore, H C /A6 forms seven hydrogen bonds with GD1a at Sia 5 , Gal 4 , and GalNAc 3 through six residues that are conserved among all BoNT/A subtypes (Figure 2) [23][24][25][26][27]. The H C /A6:GD1a interface is most similar to H C /A5, forming a total of 7 hydrogen bonds with the three monosaccharides GalNAc 3 , Gal 4 and Sia 5 [27].…”

Section: New Crystal Form Of H C /A6mentioning

confidence: 99%

“…GD1a ( Figure 1 A) constitutes one of the four major gangliosides (GM1, GD1a, GT1b and GD1b [ 22 ]) that make up 80–90% [ 20 ] of all gangliosides. The oligosaccharide moiety contains six monosaccharide units, of which the three terminal units (Sialic acid, Galactose, and N -acetylglucosamine) have been shown to form direct hydrogen bonding interactions with the H CC subdomain of BoNT subtypes (/A1 to/A5) [ 23 , 24 , 25 , 26 , 27 ]. The terminal units are conserved among GD1a and GT1b and both have been identified as binding partners with BoNT/A1 [ 28 ].…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Crystal Structures of the Clostridium botulinum Neurotoxin A6 Cell Binding Domain Alone and in Complex with GD1a Reveal Significant Conformational Flexibility

Gregory

Newell

Mojanaga

et al. 2022

IJMS

Self Cite

View full text Add to dashboard Cite

Clostridium botulinum neurotoxin A (BoNT/A) targets the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex, by cleaving synaptosomal-associated protein of 25 kDa size (SNAP-25). Cleavage of SNAP-25 results in flaccid paralysis due to repression of synaptic transmission at the neuromuscular junction. This activity has been exploited to treat a range of diseases associated with hypersecretion of neurotransmitters, with formulations of BoNT/A commercially available as therapeutics. Generally, BoNT activity is facilitated by three essential domains within the molecule, the cell binding domain (HC), the translocation domain (HN), and the catalytic domain (LC). The HC, which consists of an N-terminal (HCN) and a C-terminal (HCC) subdomain, is responsible for BoNT’s high target specificity where it forms a dual-receptor complex with synaptic vesicle protein 2 (SV2) and a ganglioside receptor on the surface of motor neurons. In this study, we have determined the crystal structure of botulinum neurotoxin A6 cell binding domain (HC/A6) in complex with GD1a and describe the interactions involved in ganglioside binding. We also present a new crystal form of wild type HC/A6 (crystal form II) where a large ‘hinge motion’ between the HCN and HCC subdomains is observed. These structures, along with a comparison to the previously determined wild type crystal structure of HC/A6 (crystal form I), reveals the degree of conformational flexibility exhibited by HC/A6.

show abstract

Section: Resultssupporting

confidence: 92%

Section: Resultsmentioning

confidence: 99%

Section: New Crystal Form Of H C /A6mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Crystal Structures of the Clostridium botulinum Neurotoxin A6 Cell Binding Domain Alone and in Complex with GD1a Reveal Significant Conformational Flexibility

Gregory

Newell

Mojanaga

et al. 2022

IJMS

Self Cite

View full text Add to dashboard Cite

show abstract

“…The wealth of structural data available on BoNT/A subtype cell-binding domains (H C /A1 to H C /A6) alone and in complex with their receptors have revealed features related to SV2 and ganglioside receptor binding [ 37 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 ]. In particular, the structure of H C /A1 in complex with human glycosylated SV2C [ 37 ] and of H C /A1 to H C /A6 in complex with the ganglioside GD1a (GM1b for H C /A5) [ 85 , 86 , 87 , 88 , 89 , 90 ] ( Table 1 ) have identified six structural features that appear to be common to the cell-binding domain ( Figure 4 ).…”

Section: Introductionmentioning

confidence: 99%

A Comprehensive Structural Analysis of Clostridium botulinum Neurotoxin A Cell-Binding Domain from Different Subtypes

Gregory

Acharya

2023

Toxins

View full text Add to dashboard Cite

Botulinum neurotoxins (BoNTs) cause flaccid neuromuscular paralysis by cleaving one of the SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) complex proteins. BoNTs display high affinity and specificity for neuromuscular junctions, making them one of the most potent neurotoxins known to date. There are seven serologically distinct BoNTs (serotypes BoNT/A to BoNT/G) which can be further divided into subtypes (e.g., BoNT/A1, BoNT/A2…) based on small changes in their amino acid sequence. Of these, BoNT/A1 and BoNT/B1 have been utilised to treat various diseases associated with spasticity and hypersecretion. There are potentially many more BoNT variants with differing toxicological profiles that may display other therapeutic benefits. This review is focused on the structural analysis of the cell-binding domain from BoNT/A1 to BoNT/A6 subtypes (HC/A1 to HC/A6), including features such as a ganglioside binding site (GBS), a dynamic loop, a synaptic vesicle glycoprotein 2 (SV2) binding site, a possible Lys–Cys/Cys–Cys bridge, and a hinge motion between the HCN and HCC subdomains. Characterising structural features across subtypes provides a better understanding of how the cell-binding domain functions and may aid the development of novel therapeutics.

show abstract

Structural basis for antiepileptic drugs and botulinum neurotoxin recognition of SV2A

Yamagata,

Ito,

Suzuki

et al. 2024

Nat Commun

View full text Add to dashboard Cite

More than one percent of people have epilepsy worldwide. Levetiracetam (LEV) is a successful new-generation antiepileptic drug (AED), and its derivative, brivaracetam (BRV), shows improved efficacy. Synaptic vesicle glycoprotein 2a (SV2A), a putative membrane transporter in the synaptic vesicles (SVs), has been identified as a target of LEV and BRV. SV2A also serves as a receptor for botulinum neurotoxin (BoNT), which is the most toxic protein and has paradoxically emerged as a potent reagent for therapeutic and cosmetic applications. Nevertheless, no structural analysis on AEDs and BoNT recognition by full-length SV2A has been available. Here we describe the cryo-electron microscopy structures of the full-length SV2A in complex with the BoNT receptor-binding domain, BoNT/A2 HC, and either LEV or BRV. The large fourth luminal domain of SV2A binds to BoNT/A2 HC through protein-protein and protein-glycan interactions. LEV and BRV occupy the putative substrate-binding site in an outward-open conformation. A propyl group in BRV creates additional contacts with SV2A, explaining its higher binding affinity than that of LEV, which was further supported by label-free spectral shift assay. Numerous LEV derivatives have been developed as AEDs and positron emission tomography (PET) tracers for neuroimaging. Our work provides a structural framework for AEDs and BoNT recognition of SV2A and a blueprint for the rational design of additional AEDs and PET tracers.

show abstract

Structural Features of Clostridium botulinum Neurotoxin Subtype A2 Cell Binding Domain

Cited by 5 publications

References 45 publications

Crystal Structures of the Clostridium botulinum Neurotoxin A6 Cell Binding Domain Alone and in Complex with GD1a Reveal Significant Conformational Flexibility

Crystal Structures of the Clostridium botulinum Neurotoxin A6 Cell Binding Domain Alone and in Complex with GD1a Reveal Significant Conformational Flexibility

A Comprehensive Structural Analysis of Clostridium botulinum Neurotoxin A Cell-Binding Domain from Different Subtypes

Structural basis for antiepileptic drugs and botulinum neurotoxin recognition of SV2A

Contact Info

Product

Resources

About