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PDBsum entry 1v6p
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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 atomic resolution crystal structure of atratoxin determined by single wavelength anomalous diffraction phasing.
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Authors
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X.Lou,
Q.Liu,
X.Tu,
J.Wang,
M.Teng,
L.Niu,
D.J.Schuller,
Q.Huang,
Q.Hao.
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Ref.
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J Biol Chem, 2004,
279,
39094-39104.
[DOI no: ]
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PubMed id
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Abstract
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By using single wavelength anomalous diffraction phasing based on the anomalous
signal from copper atoms, the crystal structure of atratoxin was determined at
the resolution of 1.5 A and was refined to an ultrahigh resolution of 0.87 A.
The ultrahigh resolution electron density maps allowed the modeling of 38 amino
acid residues in alternate conformations and the location of 322 of 870 possible
hydrogen atoms. To get accurate information at the atomic level, atratoxin-b (an
analog of atratoxin with reduced toxicity) was also refined to an atomic
resolution of 0.92 A. By the sequence and structural comparison of these two
atratoxins, Arg(33) and Arg(36) were identified to be critical to their varied
toxicity. The effect of copper ions on the distribution of hydrogen atoms in
atratoxin was discussed, and the interactions between copper ions and protein
residues were analyzed based on a statistical method, revealing a novel
pentahedral copper-binding motif.
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Figure 2.
FIG. 2. Dimeric representation of atratoxin linked by a
Cu2+ ion in the asymmetric unit. Molecules A and B adopt a
back-to-face orientation. Disulfide bonds are shown in brown and
purple. Four residues chelated by a copper ion are colored in
green and blue. All figures, if not specified, were prepared
with Molscript (43) and O (33).
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Figure 4.
FIG. 4. Anisotropic thermal motions of the two atratoxin
molecules in the crystallographic asymmetric unit. These figures
were prepared with RASTEP (35). The ellipsoids represent the
moving directions of atoms. The colors are assigned based on
B[eq] values. Atoms with lowest B[eq] are colored blue; atoms
with highest B[eq] are colored red; and atoms between these are
assigned color shading smoothly through a spectrum from dark
blue to light red.
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The above figures are
reprinted
by permission from the ASBMB:
J Biol Chem
(2004,
279,
39094-39104)
copyright 2004.
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