Structure of yeast cytochrome c oxidase in a supercomplex with cytochrome bc1
Structure of yeast cytochrome c oxidase in a supercomplex with cytochrome bc1
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DOI：
10.1038/s41594-018-0172-z
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发表时间：
2019-01-01
影响因子：
16.8
通讯作者：
Marechal, Amandine
中科院分区：
文献类型：
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作者：
Hartley, Andrew M.;Lukoyanova, Natalya;Marechal, Amandine
细胞色素c氧化酶（复合物IV，CIV）在哺乳动物中独立存在或与其他呼吸蛋白结合形成超复合物（SC）。在酿酒酵母中，CIV仅存在于具有细胞色素bc（1）的SC中（复合物III，CIII）。在这里，我们提出了低温电子显微镜（cryo-EM）结构的S。酿酒酵母CIV在III 2 IV 2 SC中以3.3埃的分辨率。虽然与哺乳动物同源物的总体相似性很高，但我们发现额外亚单位Cox 26和Cox 13存在显着差异;后者表现出独特的排列，排除了在牛中看到的CIV二聚化。一个构象转变的基质结构域的Cox 5A-参与变构抑制ATP-可能会产生从其协会与CIII。CIII-CIV排列突出了CIII的保守相互作用界面，尽管在哺乳动物胞内体中被复合物I占据。我们讨论了我们的研究结果的背景下，SC形成CIV监管的潜在影响。
Cytochrome c oxidase (complex IV, CIV) is known in mammals to exist independently or in association with other respiratory proteins to form supercomplexes (SCs). In Saccharomyces cerevisiae, CIV is found solely in an SC with cytochrome bc(1) (complex III, CIII). Here, we present the cryogenic electron microscopy (cryo-EM) structure of S. cerevisiae CIV in a III2IV2 SC at 3.3 angstrom resolution. While overall similarity to mammalian homologs is high, we found notable differences in the supernumerary sub-units Cox26 and Cox13; the latter exhibits a unique arrangement that precludes CIV dimerization as seen in bovine. A conformational shift in the matrix domain of Cox5A-involved in allosteric inhibition by ATP-may arise from its association with CIII. The CIII-CIV arrangement highlights a conserved interaction interface of CIII, albeit one occupied by complex I in mammalian respirasomes. We discuss our findings in the context of the potential impact of SC formation on CIV regulation.