8.9 Structural and Mechanistic Aspects of Mitochondrial Transport Proteins

摘要: Mitochondrial transport proteins, also called mitochondrial carriers or transporters, translocate nucleotides, amino acids, inorganic ions, fatty keto and cofactors across the inner membrane of mitochondria. These steps are required for generation ATP from oxidation sugars fat; breakdown, synthesis, interconversion acids; synthesis heme iron sulfur clusters; heat production; macromolecular synthesis. The proteins share several sequence features, including a signature motif PX[DE]XX[RK] three homologous acid repeats. Their structural folds consist six transmembrane α helices matrix-side that arranged with threefold pseudo-symmetry in agreement central cavity formed by contains single substrate binding site flanked two conserved symmetrical triplets positively negatively charged residues have propensity to form salt bridge networks. During cycle, disruption formation networks might be coupled opening closing protein on either side an alternating manner.