* AMP, GMP, dAMP, dGMP IMP, XMP *ADP, GDP, dADP, dGDP *ATP, GTP, dATP, dGTP
• Anabolism
*de novo synthesis pathway *salvage pathway
• Catabolism
de novo synthesis of purine nucleotides
PRPP synthetase
(Ⅰ)
1
(Ⅱ)
.
9
amidotransferase
(Ⅱ)
2
(PRA)
(Ⅲ)
7
5 4
9
9
3
4
(Ⅲ)
5 34
7 8
9
(Ⅳ) (GAR)
8
H2O 6
7
5 34
Ring closure 9
(Ⅶ) (AIR)
8 7
5 4 9
(Ⅴ) (FGAR) 5
(Ⅵ) (FGAM)
7 5
H2O
Ribonucleotide reductase Thioredoxin reductase
GTP
dGMP dGDP dGTP
GDP ADP GMP AMP
IMP
ATP
dAMP dADP dATP
AA, CO2, 1-carbon unit
dAMP dADP
AMP ADP
IMP
GMP GDP
• carriers of chemical energy (ATP) • components of the cofactors (NAD+, FAD, and
coenzyme A) • activated biosynthetic intermediates (UDP-