Chemistry Reference
In-Depth Information
Watson-Crick base pair
Watson-Crick base pair
Guanine
Cytosine
H
N
2
O
2
Adenine
Thymine
e
e
N
6
O
4
H
p
z
p
y
p
z
sp
2
sp
e
N
3
N
1
e
H
p
z
p
z
e
e
sp
2
sp
e
H
e
N
3
1
N
1
p
z
p
z
e
sp
2
e
sp
2
e
O
6
e
H
N
4
2
p
z
2
p
z
sp
2
sp
2
p
z
p
z
wrong pair
H
wrong pair
sp
2
sp
2
N
2
O
2
H
N
6
O
4
p
z
p
y
p
z
sp
2
H
sp
N
1
N
3
p
z
sp
z
H
sp
2
sp
2
N
3
N
1
p
z
p
z
sp
2
H
sp
2
O
6
N
4
p
z
p
z
sp
2
sp
2
p
z
p
z
sp
2
sp
2
A
B
Figure 2.11
The electron confi guration of atoms of G-C (A) and A-T (B) pairs taking part in
H-bonds before and after DPT
minor groove
N
2
G
H
O
2
N
1
H
e
N
3
e
N
7
O
6
H
N
4
C
M
n+
major groove
Figure 2.12
Double proton transfer (DPT) in a G-C pair of DNA
E
0
r
+
N
H
N
Figure 2.13
Hypothetical function of potential energy of N-H···N type H-bonds
