C-DNA


C-DNA also known as C form DNA. It is one of the many possible double helical structures of DNA. This form of DNA can be observed at some conditions such as relatively low humidity and the presence of certain ions, such as Li+ or Mg2+.
Recent research suggests that both C-DNA and B-DNA consist of two distinct nucleotide conformations, B-I and B-II. The ratio of B-II conformation in C-DNA is more than 40%. However, the ratio of B-II conformation in B-DNA is only about 10%.It has 9.33 bp/turn. This form of dna is not very stable and not very common. It has right handed helice.
In a past experiment performed, it was noted that counterions such as primary amides under basic conditions were used to show the relationship between B and C forms of DNA. The overall shape and orientations of DNA is heavily dependent on its primary sequence and hydrogen bonding between its base pairs, which stabilizes and holds the confirmation of the double helices. C-DNA was shown to hold its confirmation without water and was able to form upon dehydration . Some amides under basic conditions and low humidity showed to hold the C-form confirmation, but smoothly transitioned to B form DNA as the humidity was increased . This may suggest a strong correlation between C-form and B-form DNA, which was also seen using Lithium salt at low humidity.

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