tailieunhanh - Báo cáo khoa học: The GxxxG motif of the transmembrane domain of subunit e is involved in the dimerization/oligomerization of the yeast ATP synthase complex in the mitochondrial membrane

A conserved putative dimerization GxxxG motif located in the unique membrane-spanning segment of the ATP syn-thase subunit e was altered in yeast both by insertion of an alanine residue and by replacement of glycine by leucine residues. These alterations led to the loss of subunit gand the loss of dimeric and oligomeric forms of the yeast ATP syn-thase. Furthermore,as in null mutants devoid of either subunit e or subunit g,mitochondria displayed anomalous morphologies with onion-like structures. . | Eur. J. Biochem. 270 1875-1884 2003 FEBS 2003 doi The GxxxG motif of the transmembrane domain of subunit e is involved in the dimerization oligomerization of the yeast ATP synthase complex in the mitochondrial membrane Genevieve Arselin Marie-France Giraud Alain Dautant Jacques Vaillier Daniel Brethes Benedicte Coulary-Salin Jacques Schaeffer and Jean Velours Institut de Biochimie et Genetique Cellulaires du CNRS Universite Victor Segalen Bordeaux France A conserved putative dimerization GxxxG motif located in the unique membrane-spanning segment of the ATP synthase subunit e was altered in yeast both by insertion of an alanine residue and by replacement of glycine by leucine residues. These alterations led to the loss of subunit g and the loss of dimeric and oligomeric forms of the yeast ATP synthase. Furthermore as in uull mutanss deooid of eithrr subunit e or subunit g mitochondria dJipja idl anomalous morphologies with onion-like structures. By taking advantage of the presence of the endogenous cysteine 28 residue in the wild-type subunit e dísulííde t mdl formaiion betwenn subunits e in intact mitochondria was found to increase the stability of an oligomeric structure of the ATP synthase in digitonin extracts. The data show the involvement of the dimerization motif of subunit e in the formation of supra-molecular structures of mitochondrial ATP synthases and are in favour of the existence in the inner mitochondrial membrane of associations of ATP synthases whose masses are higher than those of ATP synthase dimers. Keywords ATP synthase oligomerization subunit e GxxxG motif yeast. The F0F1-ATP synthase is a molecular rotary motor that is responsible for the aerobic synthesis of ATP. It exhibits a headpiece catalytic sector a basepíere membrane eschar and two connecting stalks. The sector F1 containing the headpiece is a water-soluble unit retaining the ability to hydrolyse ATP when in a soluble form. F0 is embedded in the .