3FUQ

Glycosylated SV2 and Gangliosides as Dual Receptors for Botulinum Neurotoxin Serotype F

Summary for 3FUQ

• Entry DOI: 10.2210/pdb3fuq/pdb
• Related: 3FUO
• Descriptor: BoNT/F (Neurotoxin type F) (2 entities in total)
• Functional Keywords: botulinum neurotoxin, ganglioside, sv2, receptor binding, neurotoxin, toxin
• Biological source: Clostridium botulinum
• Total number of polymer chains: 1
• Total formula weight: 48447.13

Authors

Fu, Z.,Chen, C.,Barbieri, J.T.,Kim, J.-J.P.,Baldwin, M.R. (deposition date: 2009-01-14, release date: 2009-06-16, Last modification date: 2023-09-06)

Primary citation

Fu, Z.,Chen, C.,Barbieri, J.T.,Kim, J.J.,Baldwin, M.R.
Glycosylated SV2 and gangliosides as dual receptors for botulinum neurotoxin serotype F
Biochemistry, 48:5631-5641, 2009

PubMed Abstract: Botulinum neurotoxin causes rapid flaccid paralysis through the inhibition of acetylcholine release at the neuromuscular junction. The seven BoNT serotypes (A-G) have been proposed to bind motor neurons via ganglioside-protein dual receptors. To date, the structure-function properties of BoNT/F host receptor interactions have not been resolved. Here, we report the crystal structures of the receptor binding domains (HCR) of BoNT/A and BoNT/F and the characterization of the dual receptors for BoNT/F. The overall polypeptide fold of HCR/A is essentially identical to the receptor binding domain of the BoNT/A holotoxin, and the structure of HCR/F is very similar to that of HCR/A, except for two regions implicated in neuronal binding. Solid phase array analysis identified two HCR/F binding glycans: ganglioside GD1a and oligosaccharides containing an N-acetyllactosamine core. Using affinity chromatography, HCR/F bound native synaptic vesicle glycoproteins as part of a protein complex. Deglycosylation of glycoproteins using alpha(1-3,4)-fucosidase, endo-beta-galactosidase, and PNGase F disrupted the interaction with HCR/F, while the binding of HCR/B to its cognate receptor, synaptotagmin I, was unaffected. These data indicate that the HCR/F binds synaptic vesicle glycoproteins through the keratan sulfate moiety of SV2. The interaction of HCR/F with gangliosides was also investigated. HCR/F bound specifically to gangliosides that contain alpha2,3-linked sialic acid on the terminal galactose of a neutral saccharide core (binding order GT1b = GD1a >> GM3; no binding to GD1b and GM1a). Mutations within the putative ganglioside binding pocket of HCR/F decreased binding to gangliosides, synaptic vesicle protein complexes, and primary rat hippocampal neurons. Thus, BoNT/F neuronal discrimination involves the recognition of ganglioside and protein (glycosylated SV2) carbohydrate moieties, providing a structural basis for the high affinity and specificity of BoNT/F for neurons.

PubMed: 19476346
DOI: 10.1021/bi9002138

Experimental method

X-RAY DIFFRACTION (2.1 Å)