Basepairs involving Hoogsteen edge of Adenine and WatsonCrick edge of Uracil

Basepairs involving Hoogsteen(H) 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 H:W Trans	417/ 65	Residue Nos. 1395(B)-1390(B) PDB ID 2QAO	N9-N7...N3-C6 N1-N6...O2-C1'
A:U H:W Cis	79/ 14	Residue Nos. 2414(x)-2223(x) PDB ID 2ZJR	N1-N6...O4-C5 N9-N7...N3-C6

Basepair

(type & Orientation)

*Frequency

Example

Hydrogen bonding atoms with their precursors

A:U H:W Trans

417/
65

Residue Nos. 1395(B)-1390(B) PDB ID 2QAO

N9-N7...N3-C6

N1-N6...O2-C1'

A:U H:W Cis

79/
14

Residue Nos. 2414(x)-2223(x) PDB ID 2ZJR

N1-N6...O4-C5

N9-N7...N3-C6