Department of Biochemistry and Biophysics, Arrhenius Laboratories for Natural Sciences, Stockholm University, 10691, Stockholm, Sweden.
Chembiochem. 2018 Mar 2;19(5):444-447. doi: 10.1002/cbic.201700664. Epub 2018 Jan 25.
The Saccharomyces cerevisiae mitochondrial respiratory supercomplex factor 2 (Rcf2) plays a role in assembly of supercomplexes composed of cytochrome bc (complex III) and cytochrome c oxidase (complex IV). We expressed the Rcf2 protein in Escherichia coli, refolded it, and reconstituted it into dodecylphosphocholine (DPC) micelles. The structural properties of Rcf2 were studied by solution NMR, and near complete backbone assignment of Rcf2 was achieved. The secondary structure of Rcf2 contains seven helices, of which five are putative transmembrane (TM) helices, including, unexpectedly, a region formed by a charged 20-residue helix at the C terminus. Further studies demonstrated that Rcf2 forms a dimer, and the charged TM helix is involved in this dimer formation. Our results provide a basis for understanding the role of this assembly/regulatory factor in supercomplex formation and function.
酿酒酵母线粒体呼吸超级复合物因子 2（Rcf2）在细胞色素 bc（复合物 III）和细胞色素 c 氧化酶（复合物 IV）组成的超级复合物的组装中发挥作用。我们在大肠杆菌中表达了 Rcf2 蛋白，对其进行了重折叠，并将其重新组装到十二烷基磷酸胆碱（DPC）胶束中。通过溶液 NMR 研究了 Rcf2 的结构特性，并实现了 Rcf2 的近乎完整的骨架分配。Rcf2 的二级结构包含七个螺旋，其中五个是假定的跨膜（TM）螺旋，出乎意料的是，C 末端的一个带电荷的 20 个残基螺旋形成一个区域。进一步的研究表明，Rcf2 形成二聚体，带电荷的 TM 螺旋参与二聚体的形成。我们的结果为理解该组装/调节因子在超级复合物形成和功能中的作用提供了基础。
