The structure and hydration of the a-DNA fragment d(gggtaccc) at room temperature and low temperature
Structure:
DNA (5'-d( Gp Gp Gp Tp Ap Cp Cp C)-3'). Chain: a, b. Engineered: yes
Source:
Synthetic: yes
Resolution:
2.50Å
R-factor:
0.143
Authors:
M.Eisenstein,F.Frolow,Z.Shakked,D.Rabinovich
Key ref:
M.Eisenstein
et al.
(1990).
The structure and hydration of the A-DNA fragment d(GGGTACCC) at room temperature and low temperature.
Nucleic Acids Res,
18,
3185-3194.
PubMed id: 2356117
The structure and hydration of the A-DNA fragment d(GGGTACCC) at room temperature and low temperature.
M.Eisenstein,
F.Frolow,
Z.Shakked,
D.Rabinovich.
ABSTRACT
The DNA fragment d(GGGTACCC) was crystallized as an A-DNA duplex in the
hexagonal space group P6(1). The structure was analyzed at room temperature and
low temperature (100K) at a resolution of 2.5 A. The helical conformations at
the two temperatures are similar but the low-temperature structure is more
economically hydrated than the room-temperature one. The structure of
d(GGGTACCC) is compared to those of d(GGGTGCCC) and d(GGGCGCCC). This series of
molecules, which consists of a mismatched duplex and its two Watson-Crick
analogues, exhibits three conformational variants of the A-form of DNA, which
are correlated with the specific intermolecular interactions observed in the
various crystals. The largest differences in local conformation are displayed by
the stacking geometries of the central pyrimidine-purine and the flanking
purine-pyrimidine sites in each of the three duplexes. Stacking energy
calculations performed on the crystal structures show that the mismatched duplex
is destabilized with respect to each of the error-free duplexes, in accordance
with helix-coil transition measurements.
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