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. 606   | 1 | 2 |

Table 23.3.4.2 

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

Table 23.3.4.2 | top | pdf |
Sequence-dependent differential deformability in B-DNA. II. The Minor Canon

These generalizations are illustrated by Fig. 23.3.4.9[link], and are justified at greater length by El Hassan & Calladine (1997)[link] and Dickerson (1998a[link],b[link],c[link]).

(6) Heterogeneous steps ending in A: C-A, T-A and G-A
Steps ending in adenine, aside from A-A, tend to display (a) negative correlation between slide and roll, and between twist and roll, and (b) positive correlation between slide and twist.
 
(7) Purine-pyrimidine steps
R-Y steps display, on average, a systematic preference for negative slide and for twist below 36°.
 
(8) Relative step frequencies in sequence-specific protein–DNA complexes
Step A-A is the most common of all, and in 55% of the cases it occurs within A-tracts.
Steps containing only GC base pairs are least common, and seemingly are less compatible with formation of sequence-specific protein complexes.
 
(9) Local environment and DNA behaviour
Sequence-dependent local helix deformations are quite similar in DNA crystals and in protein–DNA complexes. DNA molecules packed against proteins in their normal biological environment appear to have more in common with DNA packed against other DNA helices in the crystal than with free DNA in solution.