Netiquette · Download · News · Gallery · Homepage · DSSR Manual · G-quadruplexes · DSSR-Jmol · DSSR-PyMOL · DSSR Licensing · Video Overview· RNA Covers
I found this definition regarding rise in the Calladine 1995 JMB paper:
Rise, Dz , is simply the component along the global
helix axis of the vector joining the mid points of
successive C6-C8 lines.
The expressions for Rise and Twist are clearly defined in a global sense, and they therefore depend on the overall conformation of an oligomer. Thus while these expressions are probably valid for, say, B-DNA oligomers where all base-pairs are nearly perpendicular to the overall fitted helix axis, they may not be appropriate for the analysis of other oligomers such as those that adopt the ‘‘A’’ form. It should be noted that since the magnitude of Helical Twist is in general substantially greater than the inclination of the base-pairs to the average best-fit helix-axis, the NH-values for Helical Twist are unlikely to be very different from those given by CEHS.
The displacements: Dx, Dy and Dz can now be obtained by resolving the vector joining the origins of the two original base-pair triads into components along the axes of the mid-step triad.
Created and maintained by Dr. Xiang-Jun Lu [律祥俊] (xiangjun@x3dna.org)
The Bussemaker Laboratory at the Department of Biological Sciences, Columbia University.