Basepairs involving Hoogsteen(H) edge of Cytosine and Sugar(S) edge of Cytosine 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

C:C h:s Cis

9/
7

Optimized Model Structure

N3-O2...N4-N3

C6-O2'...C5-C1'

C:C h:s Trans

9/
2

Optimized Model Structure

N3-O2...C5-N1

C6-O2'...N4-N3

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