3. The Family of DNAs
A-DNA (left), B-DNA (middle) and Z-DNA (right) -- 12 bp each
From Dickerson et al. in Cold Spring Harbor Symposium for
Quantitative Biology
(1982) v47 p13-24.
3 families
of DNA helices:
A-DNA
family - this is most common for double stranded RNA, RNA/DNA hybrids,
as well as for certain DNA sequences, such as long stretches of purines.
B-DNA family
- DNA exists in the "B-DNA form", most of the time inside the cells of
living organisms. This is the classical "Watson-Crick" structure.
B-DNA
Z-DNA
family - this is much more rare than the other two families, although certains
sequences (such as runs of GC repeats (GCGCGC)) can form Z-DNA easily.