Buy article online - an online subscription or single-article purchase is required to access this article.
Download citation
Download citation
link to html
X-ray crystal structures of the spermine4+ form of the Z-DNA duplex with the self-complementary d(CG)3 sequence in complexes with Mn2+ and Zn2+ cations have been determined at the ultrahigh resolutions of 0.75 and 0.85 Å, respectively. Stereochemical restraints were only used for the sperminium cation (in both structures) and for nucleotides with dual conformation in the Zn2+ complex. The Mn2+ and Zn2+ cations at the major site, designated M2+(1), bind at the N7 position of G6 by direct coordination. The coordination geometry of this site was octahedral, with complete hydration shells. An additional Zn2+(2) cation was bis-coordinated in a tetrahedral fashion by the N7 atoms of G10 and G12 from a symmetry-related molecule. The coordination distances of Zn2+(1) and Zn2+(2) to the O6 atom of the guanine residues were 3.613 (6) and 3.258 (5) Å, respectively. Moreover, a chloride ion was also identified in the coordination sphere of Zn2+(2). Alternate conformations were observed in the Z-DNA-Zn2+ structure not only at internucleotide linkages but also at the terminal C3'-OH group of G12. The conformation of the sperminium chain in the Z-DNA-Mn2+ complex is similar to the spermine4+ conformation in analogous Z-DNA-Mg2+ structures. In the Z-­DNA-Zn2+ complex the sperminium cation is disordered and partially invisible in electron-density maps. In the Z-­DNA-Zn2+ complex the sperminium cation only interacts with the phosphate groups of the Z-DNA molecules, while in the Z-­DNA-Mn2+ structure it forms hydrogen bonds to both the phosphate groups and DNA bases.
Keywords: Z-DNA; d(CG)3; Mn2+; Zn2+.

Supporting information

pdf

Portable Document Format (PDF) file https://doi.org/10.1107/S0907444913007798/dz5281sup1.pdf
Supplementary material

PDB references: Z-DNA in complex with Mn2+, 4hig; Z-­DNA in complex with Zn2+, 4hif


Subscribe to Acta Crystallographica Section D: Biological Crystallography

The full text of this article is available to subscribers to the journal.

If you have already registered and are using a computer listed in your registration details, please email support@iucr.org for assistance.

Buy online

You may purchase this article in PDF and/or HTML formats. For purchasers in the European Community who do not have a VAT number, VAT will be added at the local rate. Payments to the IUCr are handled by WorldPay, who will accept payment by credit card in several currencies. To purchase the article, please complete the form below (fields marked * are required), and then click on `Continue'.
E-mail address* 
Repeat e-mail address* 
(for error checking) 

Format*   PDF (US $40)
   HTML (US $40)
   PDF+HTML (US $50)
In order for VAT to be shown for your country javascript needs to be enabled.

VAT number 
(non-UK EC countries only) 
Country* 
 

Terms and conditions of use
Contact us

Follow Acta Cryst. D
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds