2DND

A BIFURCATED HYDROGEN-BONDED CONFORMATION IN THE D(A.T) BASE PAIRS OF THE DNA DODECAMER D(CGCAAATTTGCG) AND ITS COMPLEX WITH DISTAMYCIN

2DND の概要

• エントリーDOI: 10.2210/pdb2dnd/pdb
• 分子名称: DNA (5'-D(*CP*GP*CP*AP*AP*AP*TP*TP*TP*GP*CP*G)-3'), DISTAMYCIN A (3 entities in total)
• 機能のキーワード: b-dna, double helix, complexed with drug, dna
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 7806.32

構造登録者

Coll, M.,Frederick, C.A.,Wang, A.H.-J.,Rich, A. (登録日: 1988-08-29, 公開日: 1989-01-09, 最終更新日: 2024-02-14)

主引用文献

Coll, M.,Frederick, C.A.,Wang, A.H.,Rich, A.
A bifurcated hydrogen-bonded conformation in the d(A.T) base pairs of the DNA dodecamer d(CGCAAATTTGCG) and its complex with distamycin.
Proc.Natl.Acad.Sci.USA, 84:8385-8389, 1987

PubMed Abstract: The crystal structures of d(CGCA3T3GCG) complex to the antitumor drug distamycin and the DNA fragment alone were solved by x-ray diffraction at 2.2 and 2.5 A resolution, respectively. The drug lies in the narrow minor groove near the center of the B-DNA fragment covering 5 of the 6 A.T base pairs. It is bound to the DNA by hydrogen bonding, van der Waals, and electrostatic interactions. In addition, the DNA was found to have an unusual conformation in the (dA)3.(dT)3 regions. These base pairs have a high positive propeller twist so that in the major groove the adenine amino group is located intermediate between the carbonyl O-4 groups of two adjacent thymines of the opposite strand, making bifurcated hydrogen bonds to the two thymine residues. This suggests a model to explain the unusual properties of poly-(dA).poly(dT) in which a modified B conformation is associated with a large propeller twist of the bases and a set of continuous bifurcating hydrogen bonds along the major groove, which may provide incremental stability to these segments. In addition, shorter segments of (dA)3-6.(dT)3-6 may have this conformation in the midst of B-DNA and stabilize bends in the DNA that may be associated with stacking on one of the high propeller-twisted bases at the ends of these segments.

PubMed: 3479798
DOI: 10.1073/pnas.84.23.8385

実験手法

X-RAY DIFFRACTION (2.2 Å)