A-DNA
Sign in to saveright|200px|thumb|alt="The A-DNA structure"|The A-DNA structure.
Article
7 sectionsContents
- Structure
- Comparison geometries of the most common DNA forms
- A/B intermediates
- Biological function
- See also
- References
- External links
right|200px|thumb|alt="The A-DNA structure"|The A-DNA structure.
A-DNA is one of the possible double helical structures which DNA can adopt. A-DNA is thought to be one of three biologically active double helical structures along with B-DNA and Z-DNA. It is a right-handed double helix fairly similar to the more common B-DNA form, but with a shorter, more compact helical structure whose base pairs are not perpendicular to the helix-axis as in B-DNA. It was discovered by Rosalind Franklin, who also named the A and B forms. She showed that DNA is driven into the A form when under dehydrating conditions. Such conditions are commonly used to form crystals, and many DNA crystal structures are in the A form. The same helical conformation occurs in double-stranded RNAs, and in DNA-RNA hybrid double helices.