Respiratory chain supercomplexes associate with the cysteine desulfurase complex of the iron-sulfur cluster assembly machinery
Böttinger L, Mårtensson CU, Song J, Zufall N, Wiedemann N, Becker T.
Mitochondria are the powerhouses of the cell. Respiratory chain complexes generate a proton gradient across the inner mitochondrial membrane that is used by the ATP synthase to generate ATP for cellular functions. In baker´s yeast Saccharomyces cerevisiae the respiratory chain consists of the succinate dehydrogenase (complex II), the cytochrome c reductase (complex III) and cytochrome c oxidase (complex IV). The respiratory chain complexes III and IV form supercomplexes. Iron-sulfur clusters (ISC) form a reactive centres of the respiratory chain complexes. They are formed within the mitochondrial matrix, a process that is essential for cell viability. The cysteine desulfurase complex (ISD) provide sulfur for ISC formation. Surprisingly, we found that the active and assembled ISD complex associates selectively with respiratory chain supercomplexes. We propose that this interaction represents a novel mechanism to adjust ISC formation to the increased demands to respiratory growth.
