Structural highlights
Function
[BXB_CLOBO] Botulinum toxin acts by inhibiting neurotransmitter release. It binds to peripheral neuronal synapses, is internalized and moves by retrograde transport up the axon into the spinal cord where it can move between postsynaptic and presynaptic neurons. It inhibits neurotransmitter release by acting as a zinc endopeptidase that cleaves the '76-Gln-|-Phe-77' bond of synaptobrevin-2.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Botulinum neurotoxin serotype B is a zinc protease that disrupts neurotransmitter release by cleaving synaptobrevin-II (Sb2), one of three SNARE proteins involved in neuronal synaptic vesicle fusion. The three-dimensional crystal structure of the apo botulinum neurotoxin serotype B catalytic domain (BoNT/B-LC) has been determined to 2.2 A resolution, and the complex of cleaved Sb2 with the catalytic domain (Sb2-BoNT/B-LC) has been determined to 2.0 A resolution. A comparison of the holotoxin catalytic domain and the isolated BoNT/B-LC structure shows a rearrangement of three active site loops. This rearrangement exposes the BoNT/B active site. The Sb2-BoNT/B-LC structure illustrates two distinct binding regions, which explains the specificity of each botulinum neurotoxin for its synaptic vesicle protein. This observation provides an explanation for the proposed cooperativity between binding of full-length substrate and catalysis and suggest a mechanism of synaptobrevin proteolysis employed by the clostridial neurotoxins.
Cocrystal structure of synaptobrevin-II bound to botulinum neurotoxin type B at 2.0 A resolution.,Hanson MA, Stevens RC Nat Struct Biol. 2000 Aug;7(8):687-92. PMID:10932255[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Hanson MA, Stevens RC. Cocrystal structure of synaptobrevin-II bound to botulinum neurotoxin type B at 2.0 A resolution. Nat Struct Biol. 2000 Aug;7(8):687-92. PMID:10932255
