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A DNA G-quadruplex/i-motif hybrid

DNA can form many structures beyond the canonical Watson–Crick double helix. It is now clear that noncanonical structures are present in genomic DNA and have biological functions. G-rich G-quadruplexes and C-rich i-motifs are the most well-characterized noncanonical DNA motifs that have been detecte...

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Autores principales: Chu, Betty, Zhang, Daoning, Paukstelis, Paul J
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Oxford University Press 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7145706/
https://www.ncbi.nlm.nih.gov/pubmed/31724696
http://dx.doi.org/10.1093/nar/gkz1008
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author Chu, Betty
Zhang, Daoning
Paukstelis, Paul J
author_facet Chu, Betty
Zhang, Daoning
Paukstelis, Paul J
author_sort Chu, Betty
collection PubMed
description DNA can form many structures beyond the canonical Watson–Crick double helix. It is now clear that noncanonical structures are present in genomic DNA and have biological functions. G-rich G-quadruplexes and C-rich i-motifs are the most well-characterized noncanonical DNA motifs that have been detected in vivo with either proscribed or postulated biological roles. Because of their independent sequence requirements, these structures have largely been considered distinct types of quadruplexes. Here, we describe the crystal structure of the DNA oligonucleotide, d(CCAGGCTGCAA), that self-associates to form a quadruplex structure containing two central antiparallel G-tetrads and six i-motif C–C(+) base pairs. Solution studies suggest a robust structural motif capable of assembling as a tetramer of individual strands or as a dimer when composed of tandem repeats. This hybrid structure highlights the growing structural diversity of DNA and suggests that biological systems may harbor many functionally important non-duplex structures.
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spelling pubmed-71457062020-04-13 A DNA G-quadruplex/i-motif hybrid Chu, Betty Zhang, Daoning Paukstelis, Paul J Nucleic Acids Res Structural Biology DNA can form many structures beyond the canonical Watson–Crick double helix. It is now clear that noncanonical structures are present in genomic DNA and have biological functions. G-rich G-quadruplexes and C-rich i-motifs are the most well-characterized noncanonical DNA motifs that have been detected in vivo with either proscribed or postulated biological roles. Because of their independent sequence requirements, these structures have largely been considered distinct types of quadruplexes. Here, we describe the crystal structure of the DNA oligonucleotide, d(CCAGGCTGCAA), that self-associates to form a quadruplex structure containing two central antiparallel G-tetrads and six i-motif C–C(+) base pairs. Solution studies suggest a robust structural motif capable of assembling as a tetramer of individual strands or as a dimer when composed of tandem repeats. This hybrid structure highlights the growing structural diversity of DNA and suggests that biological systems may harbor many functionally important non-duplex structures. Oxford University Press 2019-12-16 2019-11-14 /pmc/articles/PMC7145706/ /pubmed/31724696 http://dx.doi.org/10.1093/nar/gkz1008 Text en © The Author(s) 2019. Published by Oxford University Press on behalf of Nucleic Acids Research. http://creativecommons.org/licenses/by/4.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Structural Biology
Chu, Betty
Zhang, Daoning
Paukstelis, Paul J
A DNA G-quadruplex/i-motif hybrid
title A DNA G-quadruplex/i-motif hybrid
title_full A DNA G-quadruplex/i-motif hybrid
title_fullStr A DNA G-quadruplex/i-motif hybrid
title_full_unstemmed A DNA G-quadruplex/i-motif hybrid
title_short A DNA G-quadruplex/i-motif hybrid
title_sort dna g-quadruplex/i-motif hybrid
topic Structural Biology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7145706/
https://www.ncbi.nlm.nih.gov/pubmed/31724696
http://dx.doi.org/10.1093/nar/gkz1008
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