Basepairs involving Sugar edge of Cytosine and WatsonCrick edge of Uracil

Basepairs involving Sugar(S) edge of Cytosine 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
C:U S:W Cis	5	Optimized Model Structure	C5-O2...N3-C6 C6-O2'...O2-C1'
C:U S:W Trans	2	Optimized Model Structure	C5-O2...N3-C6 C6-O2'...O4-C5

Basepair

(type & Orientation)

*Frequency

Example

Hydrogen bonding atoms with their precursors

C:U S:W Cis

Optimized Model Structure

C5-O2...N3-C6

C6-O2'...O2-C1'

C:U S:W Trans

Optimized Model Structure

C5-O2...N3-C6

C6-O2'...O4-C5