The Base Pair Directory

UU base pairs with two standard hydrogen bonds
base  potential H-bond donor/acceptor sites
uracil U

U(1da3) 

O4...
C4
N3-H...

U(2da3)

N3-H...
C2
O2...
UU base pairs with 4 heavy-atom H-bond donor/acceptor sites
base pair H-bond motif structure images

U(2da3)...U(2da3)

UU 2-carbonyl-N3, symmetric
  

O2...H-N3
C2     C2
N3-H...O2
  • Tinoco compilation: 
    • yes (pyrimidine-pyrimidine base pairs, U.U 2-carbonyl-N3, symmetric) 
  • Westhof compilation: 
  • Jeffrey/Saenger compilation: 
    • yes (UU6) 
PDF | VRML

U(1da3)...U(1da3)

UU 4-carbonyl-N3, symmetric 
  

N3-H...O4
C4     C4
O4...H-N3
  • Tinoco compilation: 
    • yes (pyrimidine-pyrimidine base pairs, U.U 4-carbonyl-N3, symmetric) 
  • Westhof compilation: 
  • Jeffrey/Saenger compilation: 
    • yes (UU4) 
PDF | VRML

U(1da3)...U(2da3)

UU 2-carbonyl-N3, 4-carbonyl-N3
  

O2...H-N3
C2     C4
N3-H...O4
  • Tinoco compilation: 
    • yes (pyrimidine-pyrimidine base pairs, U.U 2-carbonyl-N3, 4-carbonyl-N3) 
  • Westhof compilation: 
  • Jeffrey/Saenger compilation: 
    • yes (UU5) 
PDF | VRML
There are no possible UU base pairs with 3 heavy-atom H-bond donor/acceptor sites.