6ZX6 image
Entry Detail
PDB ID:
6ZX6
Keywords:
Title:
Antiparallel basket-type G-quadruplex DNA structure formed in human Bcl-2 promoter containing 8-oxoG
Biological Source:
Source Organism:
PDB Version:
Deposition Date:
2020-07-29
Release Date:
2021-03-10
Method Details:
Experimental Method:
Conformers Calculated:
100
Conformers Submitted:
12
Selection Criteria:
structures with the lowest energy
Macromolecular Entities
Polymer Type:polydeoxyribonucleotide
Description:bcl2ex-oxoG19
Chain IDs:A
Chain Length:25
Number of Molecules:1
Biological Source:Homo sapiens
Ligand Molecules
Primary Citation
Oxidative lesions modulate G-quadruplex stability and structure in the human BCL2 promoter.
Nucleic Acids Res. 49 2346 2356 (2021)
PMID: 33638996 DOI: 10.1093/nar/gkab057

Abstact

Misregulation of BCL2 expression has been observed with many diseases and is associated with cellular exposure to reactive oxygen species. A region upstream of the P1 promoter in the human BCL2 gene plays a major role in regulating transcription. This G/C-rich region is highly polymorphic and capable of forming G-quadruplex structures. Herein we report that an oxidative event simulated with an 8-oxo-7,8-dihydroguanine (oxoG) substitution within a long G-tract results in a reduction of structural polymorphism. Surprisingly, oxoG within a 25-nt construct boosts thermal stability of the resulting G-quadruplex. This is achieved by distinct hydrogen bonding properties of oxoG, which facilitate formation of an antiparallel basket-type G-quadruplex with a three G-quartet core and a G·oxoG·C base triad. While oxoG has previously been considered detrimental for G-quadruplex formation, its stabilizing effect within a promoter described in this study suggests a potential novel regulatory role of oxidative stress in general and specifically in BCL2 gene transcription.

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Primary Citation of related structures