7DO1

Solution structure of a heteromolecular telomeric (3+1) G-quadruplex containing right loop progression

Summary for 7DO1

• Entry DOI: 10.2210/pdb7do1/pdb
• Descriptor: DNA (5'-D(*GP*GP*GP*TP*TP*AP*GP*GP*GP*TP*TP*AP*GP*GP*G)-3'), DNA (5'-D(*TP*TP*AP*GP*GP*G)-3') (2 entities in total)
• Functional Keywords: hybrid g-quadruplex, human telomere, (3+1), dna
• Biological source: Homo sapiens (Human); More
• Total number of polymer chains: 2
• Total formula weight: 6625.33

Authors

Fu, W.Q.,Jing, H.T.,Zhang, N. (deposition date: 2020-12-11, release date: 2021-09-29, Last modification date: 2024-05-15)

Primary citation

Fu, W.,Jing, H.,Xu, X.,Xu, S.,Wang, T.,Hu, W.,Li, H.,Zhang, N.
Two coexisting pseudo-mirror heteromolecular telomeric G-quadruplexes in opposite loop progressions differentially recognized by a low equivalent of Thioflavin T.
Nucleic Acids Res., 49:10717-10734, 2021

PubMed Abstract: The final 3'-terminal residue of the telomeric DNA G-overhang is inherently less precise. Here, we describe how alteration of the last 3'-terminal base affects the mutual recognition between two different G-rich oligomers of human telomeric DNA in the formation of heteromolecular G-quadruplexes (hetero-GQs). Associations between three- and single-repeat fragments of human telomeric DNA, target d(GGGTTAGGGTTAGGG) and probe d(TAGGGT), in Na+ solution yield two coexisting forms of (3 + 1) hybrid hetero-GQs: the kinetically favourable LLP-form (left loop progression) and the thermodynamically controlled RLP-form (right loop progression). However, only the adoption of a single LLP-form has been previously reported between the same probe d(TAGGGT) and a target variant d(GGGTTAGGGTTAGGGT) having one extra 3'-end thymine. Moreover, the flanking base alterations of short G-rich probe variants also significantly affect the loop progressions of hetero-GQs. Although seemingly two pseudo-mirror counter partners, the RLP-form exhibits a preference over the LLP-form to be recognized by a low equivalent of fluorescence dye thioflavin T (ThT). To a greater extent, ThT preferentially binds to RLP hetero-GQ than with the corresponding telomeric DNA duplex context or several other representative unimolecular GQs.

PubMed: 34500466
DOI: 10.1093/nar/gkab755

Experimental method

SOLUTION NMR