Preprotein Translocase of the Outer Mitochondrial Membrane: Reconstituted Tom40 Forms a Characteristic TOM Pore
| Autor: | Rita Casadio, Richard Wagner, Lars Becker, Georg E. Schulz, Kerstin Hill, Kaye N. Truscott, Kirstin Model, Nikolaus Pfanner, Thomas Krimmer, Michael Bannwarth, Chris Meisinger |
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| Přispěvatelé: | L. Becker, M. Bannwarth, C. Meisinger, K. Hill, K. Model, T. Krimmer, Casadio R., Truscott K.N., G.E. Schulz, N. Pfanner, R. Wagner |
| Rok vydání: | 2005 |
| Předmět: |
Saccharomyces cerevisiae Proteins
Translocase of the outer membrane PROTEIN SORTING TIM/TOM complex medicine.disease_cause Mitochondrial Membrane Transport Proteins Protein Structure Secondary Fungal Proteins Mitochondrial Proteins Mitochondrial membrane transport protein MITOCHONDRIA Structural Biology Mitochondrial Precursor Protein Import Complex Proteins Protein targeting medicine Translocase Molecular Biology SACCHAROMYCES CEREVISIAE TOM COMPLEX Binding Sites Neurospora crassa biology Vesicle Membrane Transport Proteins Cell biology Electrophysiology Mitochondrial Membranes Translocase of the inner membrane biology.protein Carrier Proteins Bacterial outer membrane |
| Zdroj: | Journal of Molecular Biology. 353:1011-1020 |
| ISSN: | 0022-2836 |
| DOI: | 10.1016/j.jmb.2005.09.019 |
| Popis: | Tom40 is the central pore-forming component of the translocase of the outer mitochondrial membrane (TOM complex). Different views exist about the secondary structure and electrophysiological characteristics of Tom40 from Saccharomyces cerevisiae and Neurospora crassa. We have directly compared expressed and renatured Tom40 from both species and find a high content of beta-structure in circular dichroism measurements in agreement with refined secondary structure predictions. The electrophysiological characterization of renatured Tom40 reveals the same characteristics as the purified TOM complex or mitochondrial outer membrane vesicles, with two exceptions. The total conductance of the TOM complex and outer membrane vesicles is twofold higher than the total conductance of renatured Tom40, consistent with the presence of two TOM pores. TOM complex and outer membrane vesicles possess a strongly enhanced sensitivity to a mitochondrial presequence compared to Tom40 alone, in agreement with the presence of several presequence binding sites in the TOM complex, suggesting a role of the non-channel Tom proteins in regulating channel activity. |
| Databáze: | OpenAIRE |
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