Basepairs involving Sugar edge of Adenine and Hoogsteen edge of Uracil

Basepairs involving Sugar(S) edge of Adenine and Hoogsteen(H) 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:h Cis	2	Optimized Model Structure	C5-N3...C5-N1 C6-C2...O4-N3
A:U s:h Trans	2/ 2	Optimized Model Structure	C5-N3...C5-C2 C8-O2'...O4-N3

Basepair

(type & Orientation)

*Frequency

Example

Hydrogen bonding atoms with their precursors

A:U s:h Cis

Optimized Model Structure

C5-N3...C5-N1

C6-C2...O4-N3

A:U s:h Trans

2/
2

Optimized Model Structure

C5-N3...C5-C2

C8-O2'...O4-N3