6JKN

Crystal Structure of G-quadruplex Formed by Bromo-substituted Human Telomeric DNA

Summary for 6JKN

• Entry DOI: 10.2210/pdb6jkn/pdb
• Descriptor: DNA (5'-D(*GP*GP*GP*TP*TP*AP*GP*(BGM)P*GP*TP*TP*AP*GP*GP*GP*TP*TP*AP*GP*(BGM)P*G)-3'), POTASSIUM ION (3 entities in total)
• Functional Keywords: dna, g-quadruplex
• Biological source: Homo sapiens
• Total number of polymer chains: 1
• Total formula weight: 6945.38

Authors

Geng, Y.,Cai, Q.,Liu, C.,Zhu, G. (deposition date: 2019-03-01, release date: 2019-04-03, Last modification date: 2024-03-27)

Primary citation

Geng, Y.,Liu, C.,Zhou, B.,Cai, Q.,Miao, H.,Shi, X.,Xu, N.,You, Y.,Fung, C.P.,Din, R.U.,Zhu, G.
The crystal structure of an antiparallel chair-type G-quadruplex formed by Bromo-substituted human telomeric DNA.
Nucleic Acids Res., 47:5395-5404, 2019

PubMed Abstract: Human telomeric guanine-rich DNA, which could adopt different G-quadruplex structures, plays important roles in protecting the cell from recombination and degradation. Although many of these structures were determined, the chair-type G-quadruplex structure remains elusive. Here, we present a crystal structure of the G-quadruplex composed of the human telomeric sequence d[GGGTTAGG8GTTAGGGTTAGG20G] with two dG to 8Br-dG substitutions at positions 8 and 20 with syn conformation in the K+ solution. It forms a novel three-layer chair-type G-quadruplex with two linking trinucleotide loops. Particularly, T5 and T17 are coplanar with two water molecules stacking on the G-tetrad layer in a sandwich-like mode through a coordinating K+ ion and an A6•A18 base pair. While a twisted Hoogsteen A12•T10 base pair caps on the top of G-tetrad core. The three linking TTA loops are edgewise and each DNA strand has two antiparallel adjacent strands. Our findings contribute to a deeper understanding and highlight the unique roles of loop and water molecule in the folding of the G-quadruplex.

PubMed: 30957851
DOI: 10.1093/nar/gkz221

Experimental method

X-RAY DIFFRACTION (1.401 Å)