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Title
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Crystal structure of the DsbA protein required for disulphide bond formation in vivo.
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Authors
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J.L.Martin,
J.C.Bardwell,
J.Kuriyan.
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Ref.
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Nature, 1993,
365,
464-468.
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PubMed id
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Abstract
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Proteins that contain disulphide bonds are often slow to fold in vitro because
the oxidation and correct pairing of the cysteine residues is rate limiting. The
folding of such proteins is greatly accelerated in Escherichia coli by DsbA, but
the mechanism of this rate enhancement is not well understood. Here we report
the crystal structure of oxidized DsbA and show that it resembles closely the
ubiquitous redox protein thioredoxin, despite very low sequence similarity. An
important difference, however, is the presence of another domain which forms a
cap over the thioredoxin-like active site of DsbA. The redox-active disulphide
bond, which is responsible for the oxidation of substrates, is thus at a domain
interface and is surrounded by grooves and exposed hydrophobic side chains.
These features suggest that DsbA might act by binding to partially folded
polypeptide chains before oxidation of cysteine residues.
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