Structure of spinach chloroplast F1-ATPase complexed with the phytopathogenic inhibitor tentoxin
Structure of spinach chloroplast F1-ATPase complexed with the phytopathogenic inhibitor tentoxin
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DOI：
10.1073/pnas.052546099
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发表时间：
2002-03-19
影响因子：
11.1
通讯作者：
Groth, G
中科院分区：
文献类型：
--
作者：
Groth, G
Tentoxin是由链格孢属真菌产生的一种天然环状四肽，在某些敏感植物中影响叶绿体F-1-ATPase的催化功能。在这项研究中，我们表明，非竞争性抑制剂tentoxin结合到叶绿体F-1-ATP酶的质膜-界面中的裂缝定位在betaAsp-83。大多数结合位点位于非催化性α亚基上。tentoxin抑制的CF 1-复合物的晶体结构表明，抑制剂与催化β-亚基中的Asp-83氢键结合，但与相邻α-亚基中的残基Ile-63、Leu-65、瓦尔-75、Tyr-237、Leu-238和Met-274形成疏水接触。除了tentoxin结合位点周围的微小变化外，叶绿体α（3）β（3）-核心复合物的结构与天然叶绿体ATP酶的结构相同。Tentoxin似乎通过抑制亚基间的接触，并通过阻断催化机制中的结合位点的相互转化。
Tentoxin, a natural cyclic tetrapeptide produced by phytopathogenic fungi from the Alternaria species affects the catalytic function of the chloroplast F-1-ATPase in certain sensitive species of plants. In this study, we show that the uncompetitive inhibitor tentoxin binds to the alphabeta-interface of the chloroplast F-1-ATPase in a cleft localized at betaAsp-83. Most of the binding site is located on the noncatalytic a-subunit. The crystal structure of the tentoxin-inhibited CF1-complex suggests that the inhibitor is hydrogen bonded to Asp-83 in the catalytic beta-subunit but forms hydrophobic contacts with residues Ile-63, Leu-65, Val-75, Tyr-237, Leu-238, and Met-274 in the adjacent a-subunit. Except for minor changes around the tentoxin-binding site, the structure of the chloroplast alpha(3)beta(3)-core complex is the same as that determined with the native chloroplast ATPase. Tentoxin seems to act by inhibiting intersubunit contacts at the alphabeta-interface and by blocking the interconversion of binding sites in the catalytic mechanism.