Calculating the Secrets of Life Contributions of the Mathematical Sciences to Molecular Biology (1995) / Chapter Skim
Currently Skimming:
Pages 155-162
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 155... ...
. (Closed DNA can be used to mode!
|
From page 156... ...
(c) The plectonemically interwound form of supercoiled closed DNA.
|
From page 157... ...
Thus Lk can be quite large for closed DNA. For a relaxed circular DNA molecule of the monkey virus SV40, which has approximately 5,250 base pairs, Lk is about 500, and for bacteriophage ~ of about 4S,5 10 base pairs, Lk is about 4,620.
|
From page 159... ...
For closed DNA the twist will usually refer to the twist of one of the backbone curves, say C around the axis A, which is denoted l~w(C,A) or simply Tw.
|
From page 160... ...
The axis of the same nonplanar closed DNA is shown in two different projections obtained by rotating the molecule around the dashed line. The points Q and R on the axis help illustrate the rotation.
|
From page 161... ...
C: I A FIGURE 6.7 Cross-section of DNA. The plane perpendicular to the DNA axis A intersects the axis at the point a and intersects the backbone curve C at the point c.
|
From page 162... ...
In addition, in most cases where the DNA is closed and supercoiled, the twist is not integral (White and Bauer, 19861. The linking number, writhe, and twist of a closed DNA are related by the well-known equation (White, 1969~: Ilk = Tw + Wr.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.