TY - JOUR
T1 - The propeller DNA conformation of poly(dA).poly(dT)
AU - Aymami, Joan
AU - Coll, Miquel
AU - Frederick, Christin A.
AU - Wang, Andrew H.J.
AU - Rich, Alexander
N1 - Funding Information:
This research was supported by grants from the National Institutes of Health, the American Cancer Society, Office of Naval Research and NASA. J.A. is a recipient of a NATO postdoctoral fellowship, and M.C. is a fellow of the Fulbright Foundation.
PY - 1989/4/25
Y1 - 1989/4/25
N2 - Physical properties of the DNA duplex, poly(dA).poly(dT) differ considerably from the alternating copolymer poly(dAT). A number of molecular models have been used to describe these structures obtained from fiber X-ray diffraction data. The recent solutions of single crystal DNA dodecamer structures with segments of oligo-A.oligo-T have revealed the presence of a high propeller twist in the AT regions which is stabilized by the formation of bifurcated (three-center) hydrogen bonds on the floor of the major groove, involving the N6 amino group of adenine hydrogen bonding to two 04 atoms of adjacent thymine residues on the opposite strand. Here we show that it is possible to incorporate the features of the single crystal analysis, specifically high propeller twist, bifurcated hydrogen bonds, and a narrow minor groove, as well as the close interstrand N signal between adenine HC2 and ribose HC1' of the opposite strand, into a model that is fully compatible with the diffraction data obtained from poly(dA) poly(dT).
AB - Physical properties of the DNA duplex, poly(dA).poly(dT) differ considerably from the alternating copolymer poly(dAT). A number of molecular models have been used to describe these structures obtained from fiber X-ray diffraction data. The recent solutions of single crystal DNA dodecamer structures with segments of oligo-A.oligo-T have revealed the presence of a high propeller twist in the AT regions which is stabilized by the formation of bifurcated (three-center) hydrogen bonds on the floor of the major groove, involving the N6 amino group of adenine hydrogen bonding to two 04 atoms of adjacent thymine residues on the opposite strand. Here we show that it is possible to incorporate the features of the single crystal analysis, specifically high propeller twist, bifurcated hydrogen bonds, and a narrow minor groove, as well as the close interstrand N signal between adenine HC2 and ribose HC1' of the opposite strand, into a model that is fully compatible with the diffraction data obtained from poly(dA) poly(dT).
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U2 - 10.1093/nar/17.8.3229
DO - 10.1093/nar/17.8.3229
M3 - Article
C2 - 2726457
AN - SCOPUS:0024546938
SN - 0305-1048
VL - 17
SP - 3229
EP - 3245
JO - Nucleic Acids Research
JF - Nucleic Acids Research
IS - 8
ER -