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PDBsum entry 1tud
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References listed in PDB file
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Key reference
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Title
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The order of secondary structure elements does not determine the structure of a protein but does affect its folding kinetics.
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Authors
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A.R.Viguera,
F.J.Blanco,
L.Serrano.
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Ref.
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J Mol Biol, 1995,
247,
670-681.
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PubMed id
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Abstract
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We have analyzed the structure, stability and folding kinetics of circularly
permuted forms of alpha-spectrin SH3 domain. All the possible permutations
involving the disruption of the covalent linkage between two beta-strands
forming a beta-hairpin have been done. The different proteins constructed here
fold to a native conformation similar to that of wild-type protein, as
demonstrated by nuclear magnetic resonance and circular dichroism. Although all
the mutants have similar stabilities (they are 1 to 2 kcal mol-1 less stable
than the wild-type) their rate constants for folding and unfolding are quite
different. Protein engineering, in combination with kinetics indicates that the
folding pathway has been changed in the circularly permuted proteins. We
conclude that neither the order of secondary structure elements, nor the
preservation of any of the beta-hairpins present in this domain, is crucial for
the ability of the polypeptide to fold, but they influence the folding and
unfolding kinetics and could determine its folding pathway.
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