Basepairs involving Hoogsteen(H) edge of Adenine and WatsonCrick(W) edge of Cytosine 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:C H:W Trans

78/
9

Residue Nos. 721(0)-707(0) PDB ID 1VQO

C5-N4...N7-N9

C6-N3...N6-N1

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:C h:w Cis

0

Optimized Model Structure

C5-N7...N4-C5

C4-C8...N3-C6

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