The mitochondrial import receptor Tom70: identification of a 25 kDa core domain with a specific binding site for preproteins
| Autor: | J, Brix, G A, Ziegler, K, Dietmeier, J, Schneider-Mergener, G E, Schulz, N, Pfanner |
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| Rok vydání: | 2000 |
| Předmět: |
Protein Folding
Saccharomyces cerevisiae Proteins Membrane Proteins Saccharomyces cerevisiae Protein Sorting Signals Binding Competitive Mitochondrial Membrane Transport Proteins Peptide Fragments Recombinant Proteins Mitochondria Protein Structure Tertiary Substrate Specificity Fungal Proteins Molecular Weight Protein Transport Mitochondrial Precursor Protein Import Complex Proteins Thermodynamics Trypsin Protein Precursors Protein Binding Sequence Deletion |
| Zdroj: | Journal of molecular biology. 303(4) |
| ISSN: | 0022-2836 |
| Popis: | The mitochondrial import receptor of 70 kDa, Tom70, preferentially recognizes precursors of membrane proteins with internal targeting signals. We report the identification of a stably folded 25 kDa core domain located in the middle portion of Tom70 that contains two of the seven tetratricopeptide repeat motifs of the receptor. The core domain binds non-cleavable and cleavable preproteins carrying internal targeting signals with a specificity indistinguishable from the full-length receptor. Competition studies indicate that both types of preproteins interact with overlapping binding sites of the core domain and that at least one additional interaction site is present in the full-length receptor. We suggest a model of Tom70 function in import of membrane proteins whereby a hydrophobic preprotein concomitantly interacts with several binding sites of the receptor. |
| Databáze: | OpenAIRE |
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