C-DNA

C-DNA, also known as C-form DNA, is one of many possible double helical conformations of DNA. DNA can be induced to take this form in particular conditions such as relatively low humidity and the presence of certain ions, such as Li⁺ or Mg²⁺, but C-form DNA is not very stable and does not occur naturally in living organisms.

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%, but in B-DNA the ratio is only about 10%. C-DNA exists as a double helix with a right-handed turn and 9.33 base pairs per full turn.

Counterions such as primary amides under basic conditions have been used in experiments to show the relationship between B and C forms of DNA.^[1] The overall shape and orientation of DNA is heavily dependent on its primary sequence as well as hydrogen bonding between its base pairs, which stabilizes and maintains the double helix conformation. C-DNA was shown to hold its conformation in the absence of water and was able to form upon dehydration.[1] Some amides under basic conditions and low humidity were shown to hold the C-form conformation, 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 See

Notes

^ 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.
^ 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.
^ 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.
^ 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.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^ 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.

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.

This biochemistry article is a stub. You can help Wikipedia by expanding it.

[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.{{cite journal}}: CS1 maint: multiple names: authors list (link)

[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.

[1]

[2]

[3]

[4]

[5]