Structural basis of yeast Tim40/Mia40 as an oxidative translocator in the mitochondrial intermembrane space
| Autor: | Kayoko Terao, Shin Kawano, Mari Naoé, Shuh-ichi Nishikawa, Koji Yamano, Nobuhisa Watanabe, Toshiya Endo, Takaki Momose |
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| Rok vydání: | 2009 |
| Předmět: |
Models
Molecular Saccharomyces cerevisiae Proteins Protein Conformation Mitochondrial intermembrane space Recombinant Fusion Proteins Immunoblotting Static Electricity Saccharomyces cerevisiae Mitochondrial Membrane Transport Proteins Maltose-Binding Proteins Protein Structure Secondary Mitochondrial membrane transport protein Protein structure X-Ray Diffraction Mitochondrial Precursor Protein Import Complex Proteins Inner membrane Cysteine Disulfides Binding site Binding Sites Multidisciplinary biology Genetic Complementation Test Biological Sciences Fusion protein Protein Structure Tertiary Transport protein Biochemistry Mitochondrial Membranes Mutation biology.protein Biophysics Carrier Proteins Crystallization Hydrophobic and Hydrophilic Interactions |
| Zdroj: | Proceedings of the National Academy of Sciences. 106:14403-14407 |
| ISSN: | 1091-6490 0027-8424 |
| Popis: | The mitochondrial intermembrane space (IMS) contains many small cysteine-bearing proteins, and their passage across the outer membrane and subsequent folding require recognition and disulfide bond transfer by an oxidative translocator Tim40/Mia40 in the inner membrane facing the IMS. Here we determined the crystal structure of the core domain of yeast Mia40 (Mia40C4) as a fusion protein with maltose-binding protein at a resolution of 3 Å. The overall structure of Mia40C4 is a fruit-dish-like shape with a hydrophobic concave region, which accommodates a linker segment of the fusion protein in a helical conformation, likely mimicking a bound substrate. Replacement of the hydrophobic residues in this region resulted in growth defects and impaired assembly of a substrate protein. The Cys296-Cys298 disulfide bond is close to the hydrophobic concave region or possible substrate-binding site, so that it can mediate disulfide bond transfer to substrate proteins. These results are consistent with the growth phenotypes of Mia40 mutant cells containing Ser replacement of the conserved cysteine residues. |
| Databáze: | OpenAIRE |
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