2LSX

Solution structure of a mini i-motif

2LSX の概要

• エントリーDOI: 10.2210/pdb2lsx/pdb
• NMR情報: BMRB: 18452
• 分子名称: DNA (5'-D(P*TP*CP*GP*TP*TP*TP*CP*GP*TP*T)-3') (1 entity in total)
• 機能のキーワード: quadruplex, minor groove tetrad, hemiprotonated base pair, cylic oligonucleotide, dna
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 6033.95

構造登録者

Escaja, N.,Viladoms, J.,Garavis, M.,Villasante, A.,Pedroso, E.,Gonzalez, C. (登録日: 2012-05-09, 公開日: 2012-10-17, 最終更新日: 2024-05-15)

主引用文献

Escaja, N.,Viladoms, J.,Garavis, M.,Villasante, A.,Pedroso, E.,Gonzalez, C.
A minimal i-motif stabilized by minor groove G:T:G:T tetrads.
Nucleic Acids Res., 40:11737-11747, 2012

PubMed Abstract: The repetitive DNA sequences found at telomeres and centromeres play a crucial role in the structure and function of eukaryotic chromosomes. This role may be related to the tendency observed in many repetitive DNAs to adopt non-canonical structures. Although there is an increasing recognition of the importance of DNA quadruplexes in chromosome biology, the co-existence of different quadruplex-forming elements in the same DNA structure is still a matter of debate. Here we report the structural study of the oligonucleotide d(TCGTTTCGT) and its cyclic analog d. Both sequences form dimeric quadruplex structures consisting of a minimal i-motif capped, at both ends, by a slipped minor groove-aligned G:T:G:T tetrad. These mini i-motifs, which do not exhibit the characteristic CD spectra of other i-motif structures, can be observed at neutral pH, although they are more stable under acidic conditions. This finding is particularly relevant since these oligonucleotide sequences do not contain contiguous cytosines. Importantly, these structures resemble the loop moiety adopted by an 11-nucleotide fragment of the conserved centromeric protein B (CENP-B) box motif, which is the binding site for the CENP-B.

PubMed: 23042679
DOI: 10.1093/nar/gks911

実験手法

SOLUTION NMR