[2P-1] ポスター2（2P-01ー2P-37）

[2P-19(YSA-6)] クライオ電子顕微鏡によるClostridium perfringensが産生する二成分毒素の膜透過に伴うアンフォールディング機構の解析

^○山田 等仁¹, 吉田 徹^1,2, 川本 晃大³, 光岡 薫⁴, 岩崎 憲治^3,5, 津下 英明^1,6,7 (1.京都産業大学 生命科学部, 2. 日本女子大学 理学部 物質生物科学科, 3.大阪大学 蛋白質研究所, 4.大阪大学 超高圧電子顕微鏡センター, 5.筑波大学 生存ダイナミクス研究センター, 6.京都産業大学 タンパク質動態研究所, 7.京都産業大学 感染症分子研究センター)

Binary toxin is bacterial toxin which is composed of enzymatic component and membrane binding component. Enzymatic component is thought to pass through membrane spanning β-barrel formed by membrane binding component oligomer. It is known that there is narrow clamp with a diameter of 6 angstrom which is smaller than diameter of α-helix. To complete the translocation, enzymatic component need be unfolded or the narrow clamp need expand for larger diameter but the mechanism was not revealed. Binary toxin is classified into two groups by the amino acid sequence difference in enzymatic component. In contrast, because membrane binding component is highly conserved between the two groups, it is thought that translocational mechanism is same between them. Thus, studying with comparison in both binary toxin groups is crucially important. We determined the structure of iota toxin (Ib-pore and Ia-bound Ib-pore) produced by Clostridium perfringens using cryo-EM single particle analysis. Comparing different group binary toxin between iota toxin and already reported anthrax binary toxin provided us new findings related in intoxication mechanism. I am going to present the findings with comparison of binary toxins which were reported in this few year.