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PDBsum entry 1ge0
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Contents |
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* Residue conservation analysis
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References listed in PDB file
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Key reference
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Title
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Role of non-Glycine residues in left-Handed helical conformation for the conformational stability of human lysozyme.
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Authors
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K.Takano,
Y.Yamagata,
K.Yutani.
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Ref.
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Proteins, 2001,
44,
233-243.
[DOI no: ]
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PubMed id
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Abstract
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To understand the role of non-Gly residues in the left-handed helical
conformation for the conformational stability of a protein, the non-Gly to Gly
and Ala mutations at six left-handed residues (R21, Y38, R50, Q58, H78, and
N118) of the human lysozyme were examined. The thermodynamic parameters for
denaturation were determined using a differential scanning calorimeter, and the
crystal structures were analyzed by X-ray crystallography. If a left-handed
non-Gly had an unfavorable steric interaction between the side-chain Cbeta and
backbone, the Gly mutation would be expected to stabilize more than the Ala
mutation at the same position. For the mutant human lysozymes, however, there
were few differences in the denaturation Gibbs energy (DeltaG) between the Gly
and Ala mutants, except for the substitution at position 58. Analysis of the
changes in stability (DeltaDeltaG) based on the structures of the wild-type and
mutant proteins showed that the experimental DeltaDeltaG value of Q58G was
approximately 7 kJ/mol higher than the estimated value without consideration of
any local steric interaction. These results indicate that only Q58G increased
the stability by elimination of local constraints. The residue 58 is located at
the most rigid position in the left-handed non-Gly residues and is involved in
its enzymatic function. It can be concluded that the left-handed non-Gly
residues do not always have unfavorable strain energies as compared with Gly at
the same position.
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Figure 3.
Figure 3. Stereodrawings of the structures in the vicinity of
the mutation sites for (a) Q58G, Q58A, and wild-type; (b) H78G,
H78A, and wild-type; and (c) N118G, N118A, and wild-type human
lysozymes. Wild-type and mutant structures are superimposed.
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Figure 5.
Figure 5. Structures in the vicinity of mutation sites for
position 21 (a) wild-type, (b) R21G, and (c) R21A human
lysozymes. Thin lines and filled circles represent hydrogen
bonds and water molecules, respectively.
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The above figures are
reprinted
by permission from John Wiley & Sons, Inc.:
Proteins
(2001,
44,
233-243)
copyright 2001.
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Secondary reference #1
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Title
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Role of amino acid residues at turns in the conformational stability and folding of human lysozyme.
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Authors
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K.Takano,
Y.Yamagata,
K.Yutani.
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Ref.
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Biochemistry, 2000,
39,
8655-8665.
[DOI no: ]
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PubMed id
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