Institut für Biochemie und Molekularbiologie, Freiburg, Germany.
Mol Biol Cell. 2010 May 1;21(9):1494-504. doi: 10.1091/mbc.e09-12-1023. Epub 2010 Mar 10.
F(1)F(o)-ATP synthase is a key enzyme of oxidative phosphorylation that is localized in the inner membrane of mitochondria. It uses the energy stored in the proton gradient across the inner mitochondrial membrane to catalyze the synthesis of ATP from ADP and phosphate. Dimeric and higher oligomeric forms of ATP synthase have been observed in mitochondria from various organisms. Oligomerization of ATP synthase is critical for the morphology of the inner mitochondrial membrane because it supports the generation of tubular cristae membrane domains. Association of individual F(1)F(o)-ATP synthase complexes is mediated by the membrane-embedded F(o)-part. Several subunits were mapped to monomer-monomer-interfaces of yeast ATP synthase complexes, but only Su e (Atp21) and Su g (Atp20) have so far been identified as crucial for the formation of stable dimers. We show that two other small F(o)-components, Su k (Atp19) and Su i (Atp18) are involved in the stepwise assembly of F(1)F(o)-ATP synthase dimers and oligomers. We have identified an intermediate form of the ATP synthase dimer, which accumulates in the absence of Su i. Moreover, our data indicate that Su i facilitates the incorporation of newly synthesized subunits into ATP synthase complexes.
F(1)F(o)-ATP 合酶是一种位于线粒体内膜的氧化磷酸化的关键酶。它利用跨线粒体内膜的质子梯度中的能量，催化 ADP 和磷酸合成 ATP。已经在来自各种生物体的线粒体中观察到二聚体和更高的寡聚体形式的 ATP 合酶。ATP 合酶的寡聚化对于线粒体内膜的形态至关重要，因为它支持管状嵴膜结构域的生成。单个 F(1)F(o)-ATP 合酶复合物的缔合是通过膜嵌入的 F(o)-部分介导的。已经将几个亚基映射到酵母 ATP 合酶复合物的单体-单体界面，但迄今为止只有 Su e（Atp21）和 Su g（Atp20）被确定为形成稳定二聚体的关键。我们表明，另外两个小的 F(o)-成分 Su k（Atp19）和 Su i（Atp18）参与 F(1)F(o)-ATP 合酶二聚体和寡聚体的逐步组装。我们已经鉴定出 ATP 合酶二聚体的中间形式，它在没有 Su i 的情况下积累。此外，我们的数据表明 Su i 促进了新合成的亚基掺入 ATP 合酶复合物。
