B-DNA tour
From Proteopedia
(Difference between revisions)
| Line 18: | Line 18: | ||
Now change the display to make it show the <scene name='72/725442/Space_filling_bbone/1'>sugar-phosphate backbone as pseudo-bonds</scene> connecting the phosphate atoms. Now the bases are easier to see. Notice how they are stacked upon each other and are nearly perpendicular to the axis of the double helix. Note also that the backbone forms a smooth, continuous curve. | Now change the display to make it show the <scene name='72/725442/Space_filling_bbone/1'>sugar-phosphate backbone as pseudo-bonds</scene> connecting the phosphate atoms. Now the bases are easier to see. Notice how they are stacked upon each other and are nearly perpendicular to the axis of the double helix. Note also that the backbone forms a smooth, continuous curve. | ||
| - | You can <scene name='72/725442/Zoom_pairs/1'>look at just four of the base pairs.</scene>.You are looking into the major groove and the colors of the base pairs alternate. | + | You can <scene name='72/725442/Zoom_pairs/1'>look at just four of the base pairs.</scene>.You are looking into the major groove and the colors of the base pairs alternate. You can also <scene name='72/725442/Zoom_pairs_only/1'>looks at just the bases</scene>. |
| - | Each base pair stacks on the next similarly, as shown from <scene name='72/725442/Zoom_pairs_top/1'>this top view</scene>. A-form DNA also stacks in this way, but compare this with Z-DNA, which behaves much differently. | + | Each base pair stacks on the next similarly, as shown from <scene name='72/725442/Zoom_pairs_top/1'>this top view</scene>. This is the <scene name='72/725442/Zoom_pairs_only_top/1'>same top view of just the bases</scene>. A-form DNA also stacks in this way, but compare this with Z-DNA, which behaves much differently. |
DNA is usually found in the B form under physiological conditions. The B-form conformation is stabilized by water molecules bound to the minor groove. You can see them as red dots <scene name='72/725442/Water_spine/1'>in this view</scene>. Sometimes kinks are found in the B helix at transcriptional control regions. These kinks can either be intrinsic to the DNA sequence or caused by transcription factor binding. | DNA is usually found in the B form under physiological conditions. The B-form conformation is stabilized by water molecules bound to the minor groove. You can see them as red dots <scene name='72/725442/Water_spine/1'>in this view</scene>. Sometimes kinks are found in the B helix at transcriptional control regions. These kinks can either be intrinsic to the DNA sequence or caused by transcription factor binding. | ||
Revision as of 13:45, 21 February 2016
B-form DNA
| |||||||||||
References
R. E. Dickerson, H. R. Drew, B. N. Conner, R. M. Wing, A. V. Fratini & M. L. Kopka (1982) The anatomy of A-, B-, and Z-DNA. Science 216: 475-485 [1] JSmol in Proteopedia [2] or to the article describing Jmol [3] to the rescue.
