THE CHEMISTRY OF ENZYME ACTION
529
O
SCoA
NH
N
His
H
O
O
O
SCoA
NH
N
His
O
O
H
H
H
HO 2 C
CO 2 H
O
HN
N
His
H
HO 2 C
CO 2 H
O
HN
N
His
H
O
SCoA
NH
N
His
O
O
H
H
HO 2 C
OH
HN
N
His
CO 2 H
O
SCoA
NH
N
His
O
O
H
HO 2 C
OH
HN
N
His
CO 2 H
O
H
H
Asp
Asp
Asp
Asp
O
SCoA
NH
N
His
O
O
H
HO 2 C
OH
HN
N
His
CO 2 H
Asp
H
OH
O
OH
HO 2 C
OH
CO 2 H
HSCoA
NH
N
His
O
O
HN
N
His
Asp
H
release of products
enolization of acetyl-CoA
aldol reaction
formation of citryl-CoA
hydrolysis of thioester
Figure 13.8 Citrate synthase: mechanism of action