Abstract
We report a new function for Escherichia coli DsbC, a protein best known for disulfide bond isomerization in the periplasm. We found that DsbC regulates the redox state of the single cysteine of the L-arabinose-binding protein AraF. This cysteine, which can be oxidized to a sulfenic acid, mediates the formation of a disulfide-linked homodimer under oxidative stress conditions, preventing L-arabinose binding. DsbC, unlike the homologous protein DsbG, reduces the intermolecular disulfide, restoring AraF binding properties. Thus, our results reveal a new link between oxidative protein folding and the defense mechanisms against oxidative stress.
Keywords:
Disulfide; DsbC; Escherichia coli; Oxidative Stress; Protein Folding; Redox Regulation; Sulfenic Acid; Thioredoxin.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Sequence
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Arabinose / metabolism
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Blotting, Western
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Carrier Proteins / chemistry
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Carrier Proteins / genetics
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Carrier Proteins / metabolism
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Cyclohexanones / pharmacology
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Cysteine / metabolism
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Disulfides / metabolism
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Escherichia coli / genetics
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Escherichia coli / metabolism*
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Escherichia coli Proteins / chemistry
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Escherichia coli Proteins / genetics
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Escherichia coli Proteins / metabolism*
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Models, Molecular
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Molecular Sequence Data
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Oxidation-Reduction / drug effects
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Oxidative Stress*
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Protein Binding
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Protein Disulfide-Isomerases / chemistry
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Protein Disulfide-Isomerases / genetics
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Protein Disulfide-Isomerases / metabolism*
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Protein Multimerization
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Protein Structure, Tertiary
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Sequence Homology, Amino Acid
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Substrate Specificity
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Sulfenic Acids / metabolism
Substances
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AraF protein, E coli
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Carrier Proteins
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Cyclohexanones
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Disulfides
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Escherichia coli Proteins
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Sulfenic Acids
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dimedone
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Arabinose
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Protein Disulfide-Isomerases
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dsbC protein, E coli
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Cysteine