Supercomplex organization

S. cerevisiae mitochondria this equilibrium appears to be shifted to supercomplex organization of Complexes III and IV (Mileykovskaya et al., 2005), which may also contain Complex II as well as two peripheral NADH dehydrogenases (Boumans et al., 1998) S. cerevisiae lack Complex I and utilize the peripheral NADH dehydrogenases. FiFq-ATP synthase (Complex V) uses the electrochemical proton gradient generated in respiration to produce ATP. 

Genova, M.L., Bianchi, C. and Lenaz, G., Supercomplex organization of the mitochondrial respiratory chain and the role of the Coenzyme Q pool pathophysiological implications. Biofactors 25 (2005) 5-20. 

Fig. 11. Projection map at 20 A resolution of a negatively stained native tubular membrane of Rhodobacter sphaeroides. The basic unit, 198 A long and 112 A wide, contains an elongated S-shaped supercomplex composed of C-shaped structures facing each other. Figure source Jungas, Ranck, Rigaud, Joliot and Verm6glio (1999) Supramolecular organization ofthe photosynthetic apparatus of Rhodobacter sphaeroides. EMBO J 18 538.

Lipids in the Assembly of Membrane Proteins and Organization of Protein Supercomplexes Implications for Lipid-Linked Disorders... 

This review will focus on a combination of molecular genetic and biochemical studies on the role of primarily phosphatidylethanolamine (PE) and cardi-olipin (CL) in the folding and organization of individual membrane proteins and multicomponent supercomplexes. The results of such studies will be related to the known and possible involvement of lipids in diseases resulting from lack of proper organization of membrane proteins. Rather than being an inclusive review of protein-lipid interactions, the aim is to select specific well-documented examples of lipid-protein interactions to illustrate the broader role of lipids in determining cellular function. 

Fig. 8.4 3D structure of bovine heart supercomplex I 1III2IV1. The globular 3D structure of the supercomplex is overlayed with the crystal structures of the Complex III dimer and Complex IV monomer as indicated. The face of Complex III that interacts with Complex IV is shown in Fig. 8.3B. The close proximity of the cytochrome c binding sites on Complexes III and IV is indicated. The organization of the supercomplex and cytochrome c interaction shown in Fig. 8.5 is based on this structure. Figure adapted from (Schafer et ah, 2007)...

Zhang, M., Mileykovskaya, E. and Dowhan, W., Cardiolipin is essential for organization of complexes III and IV into a supercomplex in intact yeast mitochondria, J Biol Chem 280 (2005a) 29403-29408. 

The respiratory chain is composed of four multiple-subunit complexes, NADH dehydrogenase (complex I), succinate dehydrogenase (complex II), cytochrome c reductase (complex III) and cytochrome c oxidase (complex IV, CcO) (7). The four complexes, located in the inner mitochondrial membrane of eukaryotes and the inner cytoplasmic membrane of prokaryotes, are electronically connected by ubiquinone and cytochrome c, which transfer electrons through complex I or complex II to complex III, and finally to complex IV, where molecular oxygen is reduced to water. Concurrently, protons are pumped across the inner mitochondrial membrane of eukaryotes or the cytoplasmic membrane of prokaryotes. The proton gradient is utilized by ATP synthase (complex V) to synthesize ATP. In many organisms, the respiratory complexes and complex V are assembled into supercomplexes which have been... 

From a strictly topological standpoint, this family of polyoxovanadates (Figure 4.21) illustrates a very peculiar process of molecular organization in inorganic chemistry. Encapsulation of anions of molecules within shells themselves anionic in nature appears to influence and control the architecture of the system, and hence the use of the terms Template or guest-host supercomplexes, which are reminiscent of the chemistry of zeolites or of supramolecular organic chemistry (75). 

---