Basepairs involving Sugar(S) edge of Adenine and WatsonCrick(W) edge of Uracil is shown. Highlighted examples are found from RNA crystal structures obtained from PDB.

Base pairs stabilized by C-H...N/O interactions along with N-H...N/O hydrogen bonds

Basepair

(type & Orientation)

*Frequency

Example

Hydrogen bonding atoms with their precursors

A:U s:w Cis

19/
2

Residue Nos. 747(B)-2014(B) PDB ID 2QAO

C5-N3...N3-C2

C6-C2...O4-C5

A:U s:w Trans

9/
1

Optimized Model Structure

C5-N3...N3-C5

C6-C2...O2-C1'

* 1st and 2nd numbers in Frequency column represent the numbers of occurences as base pairs and as base triplets, respectively.