Broz Amanda K, Tovar-Méndez Alejandro, Mooney Brian P, Johnston Mark L, Miernyk Jan A, Randall Douglas D
Department of Biochemistry, University of Missouri, Columbia, MO, USA.
Department of Biochemistry, University of Missouri, Columbia, MO, USA.
Mitochondrion. 2014 Nov;19 Pt B:144-53. doi: 10.1016/j.mito.2014.05.003. Epub 2014 May 17.
The Arabidopsis thaliana genome includes three genes for mitochondrial dihydrolipoamide acetyltransferase, the E2-component of the mitochondrial pyruvate dehydrogenase complex (PDC). Two genes encode E2-proteins with a single lipoyl domain, while the third has a two-lipoyl domain structure. Transcripts for each E2 protein were expressed in all plant organs. Each recombinant AtmtE2 can individually form an icosahedral PDC core structure, and results from bimolecular fluorescence complementation assays are consistent with formation of hetero-core structures from all permutations of the AtmtE2 proteins. We propose a unique regulatory mechanism involving dynamic formation of hetero-core complexes that include both mono- and di-lipoyl forms of AtmtE2.
拟南芥基因组包含三个线粒体二氢硫辛酰胺乙酰转移酶基因，该酶是线粒体丙酮酸脱氢酶复合体（PDC）的E2亚基。两个基因编码具有单个硫辛酰结构域的E2蛋白，而第三个基因具有双硫辛酰结构域结构。每种E2蛋白的转录本在所有植物器官中均有表达。每个重组AtmtE2都能单独形成二十面体PDC核心结构，双分子荧光互补分析结果表明，AtmtE2蛋白的所有排列组合都能形成异源核心结构。我们提出了一种独特的调控机制，涉及包括单硫辛酰和双硫辛酰形式的AtmtE2在内的异源核心复合物的动态形成。
