Mutations that allow disulfide bond formation in the cytoplasm of Escherichia coli.
Disulfide bonds are rarely found in cytoplasmic proteins. Mutations were selected for in Escherichia coli that allow disulfide bond formation in the cytoplasm. In the presence of these mutations, export-defective versions of alkaline phosphatase and mouse urokinase were able to fold into their enzymatically active conformations in the cytoplasm because their disulfide bonds were formed. The mutations were mapped to the gene for thioredoxin reductase and diminish or eliminate the activity of this enzyme. Thioredoxin itself was found to be unnecessary for this disulfide bond formation. Thioredoxin reductase, but not thioredoxin, is thus implicated in keeping cysteines reduced in cytoplasmic proteins.
Derman
A I
AI
Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, MA 02115.
Prinz
W A
WA
Belin
D
D
Beckwith
J
J
D000469:Alkaline Phosphatase / Q000737:chemistry* / Q000378:metabolism; D003545:Cysteine / Q000378:metabolism; D003593:Cytoplasm / Q000201:enzymology*; D004220:Disulfides / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D005798:Genes, Bacterial; D009154:Mutation; D010084:Oxidation-Reduction; D017510:Protein Folding; D021382:Protein Sorting Signals; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D013880:Thioredoxin-Disulfide Reductase / Q000235:genetics / Q000378:metabolism*; D014568:Urokinase-Type Plasminogen Activator / Q000737:chemistry* / Q000378:metabolism
D004220:Disulfides; D021382:Protein Sorting Signals; D011994:Recombinant Proteins; D013880:Thioredoxin-Disulfide Reductase; D000469:Alkaline Phosphatase; D014568:Urokinase-Type Plasminogen Activator; D003545:Cysteine