The dodecamer of alternating A-U is shown using the Ball & Stick
display. The 5' and 3' ends of each chain are labeled.
A
single A-U base pair (distance in Å between C1' carbons).
The sugar phosphate backbone groups are white. Remove
distances.
Three stacked A-U base pairs.
A
U-A bp (Ball & Stick with dots) is stacked above an A-U base
pair (Spacefill). Note the difference in geometry between this dinucleotide
stack and that seen with the next highlight button.
The
middle A-U base pair (Ball & Stick with dots) is stacked above
the bottom U-A base pair (Spacefill).
The differences in stacking geometry is related to the fact that the
stability of RNA and DNA helices depends on the sequence of dinucleotide
units, and not on individual base pairs alone.
Place
any of the above base pairs in the original double helix.
Viewing tips:
Use the buttons to the right of the image to show only portions of the
structure; then use the Chime menu to display or color the molecule. The
rotate buttons act on the entire structure. Remove the distance monitors
with a second click.
On this and other pages that display RNA structures, the nucleotides can
be identified by choosing Shapely under the Chime Colors
menu. The Shapely colors for RNA are:
Go to the one-page display of one of these structures: