Basepairs involving WatsonCrick edge of Adenine and WatsonCrick edge of Uracil

Basepairs involving WatsonCrick(W) 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 N-H...N/O type hydrogen bonds only

Basepair (type & Orientation)	*Frequency	Example	Hydrogen bonding atoms with their precursors
A:U W:W Cis	1822/ 110	Residue Nos. 45(X)-25(X) PDB ID 1Y26	N9-N1...N3-C6 N7-N6...O4-C5
A:U W:W Trans	62/ 8	Residue Nos. 1915(D)-1948(D) PDB ID 1IL2	N9-N1...N3-C6 N7-N6...O2-C1'

Basepair

(type & Orientation)

*Frequency

Example

Hydrogen bonding atoms with their precursors

A:U W:W Cis

1822/
110

Residue Nos. 45(X)-25(X) PDB ID 1Y26

N9-N1...N3-C6

N7-N6...O4-C5

A:U W:W Trans

62/
8

Residue Nos. 1915(D)-1948(D) PDB ID 1IL2

N9-N1...N3-C6

N7-N6...O2-C1'