Forms of DNA: Difference between revisions
new source to fix failures with animated model |
rewriting the source code for the aimated transition, to fix nonfunctioning part |
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| Line 103: | Line 103: | ||
<jmolButton> | <jmolButton> | ||
<target>AtoB</target> | <target>AtoB</target> | ||
<script>spacefill only;</script> | <script>spacefill only; save state ab;</script> | ||
<text>Spacefill</text> | <text>Spacefill</text> | ||
</jmolButton> | </jmolButton> | ||
</jmol> | </jmol> | ||
</ | <scene name='43/438459/Spacefill_animated/3'>Reset the model</scene> | ||
</ | |||
<!--Group of | <!--Group of actions which show base pair shift, sugar pucker change and difference in space filling models in A and B DNA --> | ||
Other interesting views: | |||
<jmol> | <jmol> | ||
<jmolRadioGroup> | |||
<target>AtoB</target> | <target>AtoB</target> | ||
<vertical>true</vertical> | |||
<item> | <item> | ||
<script> moveto 1 | <script>moveto 1 0 0 1 0 180 0 0; spin off; select all; cartoon only; spacefill 90; wireframe 50; centre all; zoom 180; | ||
color translucent 0.9; select 9:A,4:B; hbonds calculate; hbonds 0.09; color opaque; | |||
set echo bottom centre; font echo 18 serif bold; color echo green; echo "Base pair shift between A and B DNA"; | |||
anim mode palindrome; anim on;</script> | |||
<text>Shift in base pair between A- and B- DNA</text> | |||
</item> | |||
<item> | <item> | ||
<script>moveto 1 | <script>moveto 1 0 0 1 0 400 0 0; spin off; select all; spacefill only; spacefill 90; wireframe 50; | ||
color translucent 0.9; select 9:A; color opaque; centre selected; zoom 400; | |||
set echo bottom left; font echo 18 serif bold; color echo green; echo "Change in sugar puckering |from C2' endo in B-DNA to C3' endo in A-DNA"; | |||
anim mode palindrome; anim on;</script> | |||
<text>Change in sugar puckering from C2' endo in B-DNA to C3' endo in A-DNA</text> | |||
</item> | |||
</jmolRadioGroup> | |||
</jmol> | </jmol> | ||
Source of morphs: <ref>PMID: 10734184</ref> | |||
[[Morphs|Read more about morphing]] | |||
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</jmol>--> | </jmol>--> | ||
</StructureSection> | |||
== References== | == References== | ||
<references/> | <references/> | ||
Revision as of 19:54, 18 December 2020
See DNA - History of the discovery and current applications (Hebrew)
See Also: Read more about morphing and Z-DNA
A comparative representation of the three forms of DNA
Sources [1]
| A-DNA | B-DNA | Z-DNA | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
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Change rendering:
Helical Parameters of the three forms of DNA
DNA is a very flexible molecule and has the ability to exist in various forms based on the environmental conditions. Naturally occurring DNA double helices are classified into A, B and Z-types. A and B-forms of DNA are the right handed forms whereas Z-DNA is the left handed form. When hydrated the DNA generally assumes B-form. The A conformation is found when there is little water to interact with the helix and is also the conformation adopted by the RNA. The formation of Z-DNA occurs with the methylation of deoxycytosine residues and also during transcription where negative supercoiling stabilizes it.
| Parameter | A-DNA | B-DNA | Z-DNA |
|---|---|---|---|
| Helix sense | right-handed | right-handed | left-handed |
| Residues per turn | 11 | 10.5 | 12 |
| Axial rise [Å] | 2.55 | 3.4 | 3.7 |
| Helix pitch(°) | 28 | 34 | 45 |
| Base pair tilt(°) | 20 | −6 | 7 |
| Rotation per residue (°) | 33 | 36 | -30 |
| Diameter of helix [Å] | 23 | 20 | 18 |
| Glycosidic bond configuration<br\>dA,dT,dC<br\>dG | <br\>anti<br\>anti | <br\>anti<br\>anti | <br\>anti<br\>syn |
| Sugar pucker<br\>dA,dT,dC<br\>dG | <br\>C3'-endo<br\>C3'-endo | <br\> C2'-endo<br\>C2'-endo | <br\>C2'-endo<br\>C3'-endo |
| Intrastrand phosphate-phosphate distance [Å] <br\>dA,dT,dC<br\>dG | <br\>5.9<br\>5.9 | <br\>7.0<br\>7.0 | <br\>7.0<br\> 5.9 |
| Sources: [2][3][4] | |||
Structural Transformation between A and B DNA
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References
- ↑ Nucleic Acid Canonical Coordinates https://nucleix.mbu.iisc.ac.in/nacc/index.html
- ↑ Rich A, Nordheim A, Wang AH. The chemistry and biology of left-handed Z-DNA. Annu Rev Biochem. 1984;53:791-846. PMID:6383204 doi:https://dx.doi.org/10.1146/annurev.bi.53.070184.004043
- ↑ Wang AH, Quigley GJ, Kolpak FJ, Crawford JL, van Boom JH, van der Marel G, Rich A. Molecular structure of a left-handed double helical DNA fragment at atomic resolution. Nature. 1979 Dec 13;282(5740):680-6. PMID:514347
- ↑ Sinden, Richard R (1994-01-15). DNA structure and function (1st ed.). Academic Press. pp. 398. ISBN 0-12-645750-6.
Proteopedia Page Contributors and Editors (what is this?)
Eran Hodis, Eric Martz, Michal Harel, Jaime Prilusky, Adithya Sagar, Karsten Theis, Joel L. Sussman, Angel Herraez