The Crystal Structure of a Junction Between Two Z-DNA Helices
Author(s)
Rich, Alexander; de Rosa, Matteo; de Sanctis, Daniele; Rosario, Ana Lucia; Archer, Margarida; Athanasiadis, Alekos; Carrondo, Maria Armenia; ... Show more Show less
Downloadde Rosa-2010-Crystal structure of.pdf (1.314Mb)
PUBLISHER_POLICY
Publisher Policy
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Terms of use
Metadata
Show full item recordAbstract
The double helix of DNA, when composed of dinucleotide purine-pyrimidine repeats, can adopt a left-handed helical structure called Z-DNA. For reasons not entirely understood, such dinucleotide repeats in genomic sequences have been associated with genomic instability leading to cancer. Adoption of the left-handed conformation results in the formation of conformational junctions: A B-to-Z junction is formed at the boundaries of the helix, whereas a Z-to-Z junction is commonly formed in sequences where the dinucleotide repeat is interrupted by single base insertions or deletions that bring neighboring helices out of phase. B-Z junctions are shown to result in exposed nucleotides vulnerable to chemical or enzymatic modification. Here we describe the three-dimensional structure of a Z-Z junction stabilized by Zα, the Z-DNA binding domain of the RNA editing enzyme ADAR1. We show that the junction structure consists of a single base pair and leads to partial or full disruption of the helical stacking. The junction region allows intercalating agents to insert themselves into the left-handed helix, which is otherwise resistant to intercalation. However, unlike a B-Z junction, in this structure the bases are not fully extruded, and the stacking between the two left-handed helices is not continuous.
Date issued
2010-05Department
Massachusetts Institute of Technology. Department of BiologyJournal
Proceedings of the National Academy of Sciences of the United States of America
Publisher
National Academy of Sciences
Citation
De Rosa, Matteo, et al. "Crystal structure of a junction between two Z-DNA helices." PNAS May 18, 2010 vol. 107 no. 20 9088-9092. ©2010 by the National Academy of Sciences.
Version: Final published version
ISSN
0027-8424
1091-6490