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+.

Not to be confused with complementary DNA, also known as cDNA.

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.[1] 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 [1]. 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 [1]. This may suggest a strong correlation between C-form and B-form DNA, which was also seen using Lithium salt at low humidity.[2][3][4][5]

also
  • B-DNA
  • A-DNA
  • Mechanical properties of DNA

References
  • L van Dam, M H Levitt (2000). "BII nucleotides in the B and C forms of natural-sequence polymeric DNA: A new model for the C form of DNA". Journal of Molecular Biology. 304 (4): 541–61. doi:10.1006/jmbi.2000.4194. PMID 11099379.
  1. Portugal, J.; Subirana, J.A. (September 1985). "Counterions which favour the C form of DNA". The EMBO Journal. 4 (9): 2403–2408. doi:10.1002/j.1460-2075.1985.tb03946.x. ISSN 0261-4189. PMC 554517.
  2. Marvin, D.A.; Spencer, M.; Wilkins, M.H.F.; Hamilton, L.D. (October 1961). "The molecular configuration of deoxyribonucleic acid III. X-ray diffraction study of the C form of the lithium salt". Journal of Molecular Biology. 3 (5): 547–IN14. doi:10.1016/s0022-2836(61)80021-1. ISSN 0022-2836.
  3. Portugal, Franklin H. (1977). A century of DNA : a history of the discovery of the structure and function of the genetic substance. MIT Press. ISBN 978-0-262-16067-4. OCLC 2964854.
  4. Ghosh, Bansal, Anirban, Manju (2003). "A glossary of DNA structures from A to Z". Acta Crystallographica Section D. 59 (4): 620–6. doi:10.1107/S0907444903003251. PMID 12657780.
  5. Zimmerman, S. B. (1982). "The Three-Dimensional Structure of DNA". Annual Review of Biochemistry. 51: 395–427. doi:10.1146/annurev.bi.51.070182.002143. PMID 7051961.


This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.