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-Structure paper
タイトル | Molecular architecture of black widow spider neurotoxins. |
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ジャーナル・号・ページ | Nat Commun, Vol. 12, Issue 1, Page 6956, Year 2021 |
掲載日 | 2021年11月29日 |
著者 | Minghao Chen / Daniel Blum / Lena Engelhard / Stefan Raunser / Richard Wagner / Christos Gatsogiannis / |
PubMed 要旨 | Latrotoxins (LaTXs) are presynaptic pore-forming neurotoxins found in the venom of Latrodectus spiders. The venom contains a toxic cocktail of seven LaTXs, with one of them targeting vertebrates (α- ...Latrotoxins (LaTXs) are presynaptic pore-forming neurotoxins found in the venom of Latrodectus spiders. The venom contains a toxic cocktail of seven LaTXs, with one of them targeting vertebrates (α-latrotoxin (α-LTX)), five specialized on insects (α, β, γ, δ, ε- latroinsectotoxins (LITs), and one on crustaceans (α-latrocrustatoxin (α-LCT)). LaTXs bind to specific receptors on the surface of neuronal cells, inducing the release of neurotransmitters either by directly stimulating exocytosis or by forming Ca-conductive tetrameric pores in the membrane. Despite extensive studies in the past decades, a high-resolution structure of a LaTX is not yet available and the precise mechanism of LaTX action remains unclear. Here, we report cryoEM structures of the α-LCT monomer and the δ-LIT dimer. The structures reveal that LaTXs are organized in four domains. A C-terminal domain of ankyrin-like repeats shields a central membrane insertion domain of six parallel α-helices. Both domains are flexibly linked via an N-terminal α-helical domain and a small β-sheet domain. A comparison between the structures suggests that oligomerization involves major conformational changes in LaTXs with longer C-terminal domains. Based on our data we propose a cyclic mechanism of oligomerization, taking place prior membrane insertion. Both recombinant α-LCT and δ-LIT form channels in artificial membrane bilayers, that are stabilized by Ca ions and allow calcium flux at negative membrane potentials. Our comparative analysis between α-LCT and δ-LIT provides first crucial insights towards understanding the molecular mechanism of the LaTX family. |
リンク | Nat Commun / PubMed:34845192 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 4.03 - 4.63 Å |
構造データ | EMDB-13642, PDB-7ptx: EMDB-13643, PDB-7pty: |
由来 |
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キーワード | TOXIN / Pore-forming toxin |