2QS6

Structure of a Hoogsteen antiparallel duplex with extra-helical thymines

2QS6 の概要

• エントリーDOI: 10.2210/pdb2qs6/pdb
• 分子名称: DNA (5'-D(*DAP*DTP*DAP*DTP*DAP*DTP*DCP*DT)-3') (2 entities in total)
• 機能のキーワード: hoogsteen, oligonucleotide, dna, thymines
• タンパク質・核酸の鎖数: 14
• 化学式量合計: 33608.62

構造登録者

Pous, J.,Urpi, L.,Subirana, J.A.,Gouyette, C.,Navaza, J.,Campos, J.L. (登録日: 2007-07-30, 公開日: 2008-03-25, 最終更新日: 2024-04-03)

主引用文献

Pous, J.,Urpi, L.,Subirana, J.A.,Gouyette, C.,Navaza, J.,Campos, J.L.
Stabilization by extra-helical thymines of a DNA duplex with Hoogsteen base pairs.
J.Am.Chem.Soc., 130:6755-6760, 2008

PubMed Abstract: We present the crystal structure of the DNA duplex formed by d(ATATATCT). The crystals contain seven stacked antiparallel duplexes in the asymmetric unit with A.T Hoogsteen base pairs. The terminal CT sequences bend over so that the thymines enter the minor groove and form a hydrogen bond with thymine 2 of the complementary strand in the Hoogsteen duplex. Cytosines occupy extra-helical positions; they contribute to the crystal lattice through various kinds of interactions, including a unique CAA triplet. The presence of thymine in the minor groove apparently contributes to the stability of the DNA duplex in the Hoogsteen conformation. These observations open the way toward finding under what conditions the Hoogsteen duplex may be stabilized in vivo. The present crystal structure also confirms the tendency of A.T-rich oligonucleotides to crystallize as long helical stacks of duplexes.

PubMed: 18447354
DOI: 10.1021/ja078022+

実験手法

X-RAY DIFFRACTION (3.08 Å)