Sharma Nupur, Osman Christof
Faculty of Biology, Ludwig Maximilian University Munich, D-82152 Planegg-Martinsried, Germany.
Graduate School of Life Sciences, Ludwig Maximilian University Munich, D-82152 Planegg-Martinsried, Germany.
Biol Chem. 2022 Jan 31;403(8-9):807-817. doi: 10.1515/hsz-2021-0398. Print 2022 Jul 26.
The mitochondrial respiratory chain is composed of nuclear as well as mitochondrial-encoded subunits. A variety of factors mediate co-translational integration of mtDNA-encoded proteins into the inner membrane. In , Mdm38 and Mba1 are ribosome acceptors that recruit the mitochondrial ribosome to the inner membrane, where the insertase Oxa1, facilitates membrane integration of client proteins. The protein Yme2 has previously been shown to be localized in the inner mitochondrial membrane and has been implicated in mitochondrial protein biogenesis, but its mode of action remains unclear. Here, we show that multiple copies of Yme2 assemble into a high molecular weight complex. Using a combination of bioinformatics and mutational analyses, we find that Yme2 possesses an RNA recognition motif (RRM), which faces the mitochondrial matrix and a AAA+ domain that is located in the intermembrane space. We further show that genetically interacts with , and , which links the function of Yme2 to the mitochondrial protein biogenesis machinery.
线粒体呼吸链由核编码亚基和线粒体编码亚基组成。多种因素介导线粒体DNA编码蛋白的共翻译整合到内膜中。在酵母中,Mdm38和Mba1是核糖体受体,可将线粒体核糖体招募到内膜,插入酶Oxa1在内膜促进客户蛋白的膜整合。蛋白质Yme2此前已被证明定位于线粒体内膜,并与线粒体蛋白质生物合成有关,但其作用方式仍不清楚。在这里,我们表明Yme2的多个拷贝组装成一个高分子量复合物。通过生物信息学和突变分析相结合,我们发现Yme2具有一个面向线粒体基质的RNA识别基序(RRM)和一个位于膜间隙的AAA+结构域。我们进一步表明,Yme2在基因上与Mdm38、Mba1和Oxa1相互作用,这将Yme2的功能与线粒体蛋白质生物合成机制联系起来。