Mutant Mitochondrial Elongation Factor G1 and Combined Oxidative Phosphorylation Deficiency

The causation of diseases involving the deficiency of more than one enzyme involved in the process of mitochondrial oxidative phosphorylation is unclear. This study suggests one potential cause. The authors identified mutation of a gene encoding a component of the mitochondrial translation machinery in two siblings with early fatal hepatoencephalopathy. The authors identified mutation of the mitochondrial translation machinery in two siblings with early fatal hepatoencephalopathy. Oxidative phosphorylation drives the synthesis of ATP and takes place through a series of reactions mediated by complexes I, II, III, IV, and V, which are integral to the inner mitochondrial membrane. Each complex is made up of several or many proteins. 1 , 2 For example, complex I is made up of 7 proteins encoded by mitochondrial genes and at least 39 proteins encoded by nuclear genes. Some diseases result from a deficit in a single complex. For example, Leigh's syndrome is caused by a single mutation in one of several mitochondrial and nuclear genes encoding proteins that make up, assemble, . . .