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

Base pairs stabilized by N-H...N/O type hydrogen bonds only

Basepair

(type & Orientation)

*Frequency

Example

Hydrogen bonding atoms with their precursors

A:U H:S Cis

0

Optimized Model Structure

N1-N6...O2-C5

C4-N7...O2'-C6

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 h:s Trans

19

Residue Nos. 2600(0)-2598(0) PDB ID 1VQO

C5-O2...C8-C4

C6-O2'...N6-N1

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