Johanna Koch

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Mia40 (a mitochondrial import and assembly protein) catalyzes disulfide bond formation in proteins in the mitochondrial intermembrane space. By using Cox17 (a mitochondrial copper-binding protein) as a natural substrate, we discovered that, in the presence of Mia40, the formation of native disulfides is strongly favored. The catalytic mechanism of Mia40(More)
Mia40 catalyses the oxidative folding of disulphide-containing proteins in the mitochondria. The folding pathway is directed by the formation of the first mixed disulphide between Mia40 and its substrate. Here, we employ Cox17 to elucidate the molecular determinants of this reaction. Mia40 engages initially in a dynamic non-covalent enzyme-substrate complex(More)
103. H. A. Hirsch (Universitiits-Frauenklinik Tfibingen): t0ber eine neue Modifikation der vesikourethralen Suspension Um einige Unzul~inglichkeiten der bisher gebr~iuchlichen Techniken der Inkontinenzoperation nach Marshall-Marchetti-Krantz zu vermeiden, wurde eine neue Modifikation entwickelt, bei der die Scheidenfaszie an die Fascia obturatoria und den(More)
Mia40 catalyzes oxidative protein folding in mitochondria. It contains a unique catalytic CPC dithiol flanked by a hydrophobic groove, and unlike other oxidoreductases, it forms long-lived mixed disulfides with substrates. We show that this distinctive property originates neither from particular properties of mitochondrial substrates nor from the CPC motif(More)
Secretion of proteins into the membrane-cell wall space is essential for cell wall biosynthesis and pathogenicity in Gram-positive bacteria. Folding and maturation of many secreted proteins depend on a single extracellular foldase, the PrsA protein. PrsA is a 30-kDa protein, lipid anchored to the outer leaflet of the cell membrane. The crystal structure of(More)
Infection of Escherichia coli by the filamentous phage fd starts with the binding of the N2 domain of the phage gene-3-protein to an F pilus. This interaction triggers partial unfolding of the gene-3-protein, cis → trans isomerization at Pro-213, and domain disassembly, thereby exposing its binding site for the ultimate receptor TolA. The trans-proline sets(More)
BACKGROUND Prolyl cis/trans isomerizations have long been known as critical and rate-limiting steps in protein folding. RESULTS Now it is clear that they are also used as slow conformational switches and molecular timers in the regulation of protein activity. Here we describe several such proline switches and how they are regulated. CONCLUSIONS AND(More)
FKBP12, a small human enzyme, aids protein folding by catalyzing cis-trans isomerization of peptidyl-prolyl bonds, and is involved in cell signaling pathways, calcium regulation, and the immune response. The underlying molecular mechanisms are not fully understood, but it is well-known that aromatic residues in the active site and neighboring loops are(More)