The Base Pair Directory

AA base pairs with two standard hydrogen bonds
base  potential H-bond donor/acceptor sites


 
 

adenine A

A(da3)

N6-H...
C6
N1...

A(da4)

N6-H...
C6
C5
N7...


 
 

AA base pairs with 4 heavy-atom H-bond donor/acceptor sites
base pair H-bond motif structure images

A(da3)...A(da3)

AA N1-amino symmetric
  

N6-H...N1
C6     C6
N1...H-N6
  • Tinoco compilation: 
    • yes (homo purine-purine base pairs A.A N1-amino symmetric) 
  • Westhof compilation: 
  • Jeffrey/Saenger compilation: 
    • yes (AA4) 
PDF | VRML

A(da4)...A(da4)

AA N7 -amino symmetric
  

N7...H-N6
C5     C6
C6     C5
N6-H...N7
  • Tinoco compilation: 
    • yes (homo purine-purine base pairs A.A N7-amino symmetric) 
  • Westhof compilation: 
  • Jeffrey/Saenger compilation: 
    • yes (AA1) 
PDF | VRML

A(da4)...A(da3)

AA N1-amino, N7-amino
  

N6-H...N1
C6     C6
C5     
N7...H-N6
  • Tinoco compilation: 
    • yes (homo purine-purine base pairs A.A N1-amino, N7-amino) 
  • Westhof compilation: 
  • Jeffrey/Saenger compilation: 
    • yes (AA2) 
PDF |   VRML
There are no possible AA base pairs with 3 heavy-atom H-bond donor/acceptor sites.