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PDBsum entry 1dn4
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References listed in PDB file
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Key reference
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Title
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Solvation of the left-Handed hexamer d(5brc-G-5brc-G-5 brc-G) in crystals grown at two temperatures.
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Authors
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B.Chevrier,
A.C.Dock,
B.Hartmann,
M.Leng,
D.Moras,
M.T.Thuong,
E.Westhof.
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Ref.
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J Mol Biol, 1986,
188,
707-719.
[DOI no: ]
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PubMed id
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Abstract
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Crystals of the hexadeoxyoligomer d(5BrC-G-5BrC-G-5BrC-G) were grown at
different temperatures (5 degrees C, 18 degrees C and 37 degrees C) in the
absence of divalent cations. The crystals grown at 5 degrees C did not diffract
X-rays, while those grown at 18 degrees C and 37 degrees C did. The oligomer
adopts the left-handed ZI conformation in both crystals. The main difference
resides in a more extensive hydration shell in the crystal grown at high
temperature than in the crystal grown at low temperature. The high-temperature
crystal displays a spine of hydration running deep in the minor groove and
linking exocyclic O-2 atoms of the pyrimidine rings. In both crystalline forms,
a hydrated sodium ion bound to the N-7 of a guanine ring was found. Strings of
water molecules bridging phosphate anionic oxygen atoms are found along the
backbone. The absolute values of the propeller-twist are also different in both
structures although the values of the twist are very similar. The results point
to the importance of the crystallization conditions when analysing fine
structural details like solvation properties of oligomers.
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Figure 9.
Figure 9. Stereo iew of the 2 entral bse-pairs with the solvent molecules at 4-0 A from the 2 bromine atoms. Note
the 2 water molecules H-bonding to the -4 of the cytosines.
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Figure 10.
Figure 10. Stereo view of the C7 to G12 strand with the chai of water molecules bridging the phosphate aninic
oxygen atoms.
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The above figures are
reprinted
by permission from Elsevier:
J Mol Biol
(1986,
188,
707-719)
copyright 1986.
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Headers
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