ジャーナル: FEBS J / 年: 2024 タイトル: The cryo-EM structure of the BoNT/Wo-NTNH complex reveals two immunoglobulin-like domains. 著者: Sara Košenina / Jana Škerlová / Sicai Zhang / Min Dong / Pål Stenmark / 要旨: The botulinum neurotoxin-like toxin from Weissella oryzae (BoNT/Wo) is one of the BoNT-like toxins recently identified outside of the Clostridium genus. We show that, like the canonical BoNTs, ...The botulinum neurotoxin-like toxin from Weissella oryzae (BoNT/Wo) is one of the BoNT-like toxins recently identified outside of the Clostridium genus. We show that, like the canonical BoNTs, BoNT/Wo forms a complex with its non-toxic non-hemagglutinin (NTNH) partner, which in traditional BoNT serotypes protects the toxin from proteases and the acidic environment of the hosts' guts. We here report the cryo-EM structure of the 300 kDa BoNT/Wo-NTNH/Wo complex together with pH stability studies of the complex. The structure reveals molecular details of the toxin's interactions with its protective partner. The overall structural arrangement is similar to other reported BoNT-NTNH complexes, but NTNH/Wo uniquely contains two extra bacterial immunoglobulin-like (Big) domains on the C-terminus. Although the function of these Big domains is unknown, they are structurally most similar to bacterial proteins involved in adhesion to host cells. In addition, the BoNT/Wo protease domain contains an internal disulfide bond not seen in other BoNTs. Mass photometry analysis revealed that the BoNT/Wo-NTNH/Wo complex is stable under acidic conditions and may dissociate at neutral to basic pH. These findings established that BoNT/Wo-NTNH/Wo shares the general fold of canonical BoNT-NTNH complexes. The presence of unique structural features suggests that it may have an alternative mode of activation, translocation and recognition of host cells, raising interesting questions about the activity and the mechanism of action of BoNT/Wo as well as about its target environment, receptors and substrates.
名称: Botulinum neurotoxin-like protein from Weissella oryzae in complex with its non-toxic non-hemagglutinin partner protein タイプ: COMPLEX / Entity ID: all / 由来: RECOMBINANT
分子量
実験値: NO
由来(天然)
生物種: Weissella oryzae (バクテリア)
由来(組換発現)
生物種: Escherichia coli (大腸菌)
緩衝液
ID
Specimen-ID
pH
1
1
5.5
2
2
5.5
緩衝液成分
ID
濃度
名称
Buffer-ID
1
25mM
MES
1
2
150mM
NaCl
1
3
25mM
MES
2
4
150mM
NaCl
2
試料
ID
濃度 (mg/ml)
Experiment-ID
包埋
シャドウイング
染色
凍結
1
0.7
1
NO
NO
NO
YES
2
0.2
1
NO
NO
NO
YES
試料支持
ID
Specimen-ID
グリッドの材料
グリッドのサイズ (divisions/in.)
グリッドのタイプ
1
1
COPPER
300
Quantifoil R2/2
2
2
COPPER
300
Quantifoil R1.2/1.3
急速凍結
ID
装置
凍結剤
湿度 (%)
Specimen-ID
凍結前の試料温度 (K)
Entry-ID
1
FEI VITROBOT MARK IV
ETHANE
100
1
277
8C8G
2
FEI VITROBOT MARK IV
ETHANE
100
2
277
8C8G
-
電子顕微鏡撮影
実験機器
モデル: Titan Krios / 画像提供: FEI Company
顕微鏡
モデル: FEI TITAN KRIOS
電子銃
電子線源: FIELD EMISSION GUN / 加速電圧: 300 kV / 照射モード: OTHER
電子レンズ
モード: BRIGHT FIELD / 倍率(公称値): 165000 X / 最大 デフォーカス(公称値): 3200 nm / 最小 デフォーカス(公称値): 1600 nm
解像度: 2.98 Å / 解像度の算出法: FSC 0.143 CUT-OFF / 粒子像の数: 283452 / 対称性のタイプ: POINT
原子モデル構築
プロトコル: AB INITIO MODEL / 空間: REAL
精密化
解像度: 2.98→2.98 Å / Cor.coef. Fo:Fc: 0.701 / SU B: 17.685 / SU ML: 0.302 / ESU R: 0.483 立体化学のターゲット値: MAXIMUM LIKELIHOOD WITH PHASES 詳細: HYDROGENS HAVE BEEN ADDED IN THE RIDING POSITIONS