The crystal structure of d(G-G-G-G-C-C-C-C) a model for poly(dG) · poly(dC)

217Citations
Citations of this article
17Readers
Mendeley users who have this article in their library.
Get full text

Abstract

The structure of the DNA oligomer d(G-G-G-G-C-C-C-C) has been determined at a resolution of 2.5 Å by single-crystal X-ray methods. There are two strands in the asymmetric unit, and these coil about each other to form a right-handed double-helix of the A-type with Watson-Crick hydrogen bonds between base-pairs. The helix has a shallow minor groove and a deep, water-filled major groove; almost all exposed functional groups on the DNA are hydrated, and 106 ordered solvent molecules have been found. The two d(G-G-G-G) · d(C-C-C-C) segments in the octamer exhibit similar and uniform structures, but there is a slight discontinuity at the GpC step between them. A recurring feature of the structure is the overlap of adjacent guanine bases in each GpG step, with the five-membered ring of one guanine stacking on the six-membered ring of its neighbour. There is little or no overlap between adjacent cytosine rings. Conformational parameters for these GpG steps are compared with those from other single-crystal X-ray analyses. In general, GpG steps exhibit high slide, low roll and variable twist. Models for poly(dG) · poly(dC) were generated by applying a simple rotation and translation to each of the unmodified d(G-G-G-G) · d(C-C-C-C) units. Detailed features of these models are shown to be compatible with various assays of poly(dG) · poly(dC) in solution, and are useful in understanding the polymorphic behaviour of this sequence under a variety of experimental conditions. © 1985.

Cite

CITATION STYLE

APA

McCall, M., Brown, T., & Kennard, O. (1985). The crystal structure of d(G-G-G-G-C-C-C-C) a model for poly(dG) · poly(dC). Journal of Molecular Biology, 183(3), 385–396. https://doi.org/10.1016/0022-2836(85)90009-9

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free