TY - JOUR
T1 - A stable antiparallel cytosine-thymine base pair occurring only at the end of a duplex
AU - Vanhommerig, S.A.M.
AU - Genderen, van, M.H.P.
AU - Buck, H.M.
PY - 1991
Y1 - 1991
N2 - Ultraviolet hyperchromicity experiments indicate that in DNA duplex formation, a C-T mismatch is destabilizing in the center of a duplex, but behaves as a stable base pair at the terminus of a duplex. The C-T base pair is thought to contain two hydrogen bonds, but has thermodynamic parameters (H° and G° of dissociation) that are similar to a G-C base pair. AMBER molecular mechanics calculations were performed to study the possible structural properties of DNA duplexes with central and terminal C-T combinations. These calculations also indicate that a central C-T pair destabilizes a duplex, while terminal C-T forms a stable base pair. Hydrogen bonding between cytosine and thymine occurs only in the energy-minimized structures when the helix diameter decreases and the propeller twist angle between the bases increases. These changes are found to occur only at the end of a duplex in the calculations, which may explain the experimental results.
AB - Ultraviolet hyperchromicity experiments indicate that in DNA duplex formation, a C-T mismatch is destabilizing in the center of a duplex, but behaves as a stable base pair at the terminus of a duplex. The C-T base pair is thought to contain two hydrogen bonds, but has thermodynamic parameters (H° and G° of dissociation) that are similar to a G-C base pair. AMBER molecular mechanics calculations were performed to study the possible structural properties of DNA duplexes with central and terminal C-T combinations. These calculations also indicate that a central C-T pair destabilizes a duplex, while terminal C-T forms a stable base pair. Hydrogen bonding between cytosine and thymine occurs only in the energy-minimized structures when the helix diameter decreases and the propeller twist angle between the bases increases. These changes are found to occur only at the end of a duplex in the calculations, which may explain the experimental results.
U2 - 10.1002/bip.360310908
DO - 10.1002/bip.360310908
M3 - Article
VL - 31
SP - 1087
EP - 1094
JO - Biopolymers
JF - Biopolymers
SN - 0006-3525
IS - 9
ER -