International
Tables for
Crystallography
Volume F
Crystallography of biological macromolecules
Edited by M. G. Rossmann and E. Arnold

© International Union of Crystallography 2006
International Tables for Crystallography (2006). Vol. F. ch. 23.3, p. 590   | 1 | 2 |

Figure 23.3.1.2 

R. E. Dickersona*

a Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095–1570, USA
Correspondence e-mail: red@mbi.ucla.edu

[Figure 23.3.1.2]
Figure 23.3.1.2

Infinite A-DNA helix, generated from the X-ray crystal structure of the hexamer G-G-T-A-T-A-C-C (references A2 and A7 in Table A23.3.1.1[link]) by deleting the outer base pair from each end and stacking images of the resulting truncated hexamer so their outer phosphate groups overlapped. This generates an endless helix that exhibits the local structural features of the X-ray crystal structure. Note the degree to which the A helix resembles an antiparallel double-stranded ribbon wound around an invisible helical core (the `hot wire' axis of Fig. 23.3.1.1[link]). (From Dickerson, 1983[link].) Reprinted courtesy of the estate of Irving Geis. Rights owned by Howard Hughes Medical Institute.