1. Adenosine Kinase
Yuno Lee

2. adenosine Nucleoside = adenine + ribose - β-N9-glycosidic bond.
Energy transfer
- adenosine triphosphate (ATP)
- adenosine diphosphate (ADP)
Signal transduction as cAMP.

6. AK(adenosine kinase)
Function
①ATP dependent phosphorylation of adenosine and other related nucleoside analogs to monophosphate derivatives. ②potential regulator of concentrations of extracellular adenosine and intracellular adenine nucleotides.
Subunit
monomer (by similarity).
Catalytic Activity
ATP + adenosine = ADP + AMP.
Cofactor
binds 3 magnesium ions per subunit (by similarity).

7. AK(adenosine kinase)
Enzyme Regulation
activity is inhibited by 5-iodotubercidin and 5'-amino-5'-deoxyadenosine (by similarity).
Pathway
purine salvage.
Tissue Specificity
highest expression in liver, testis, kidney and spleen.
lower expression in brain. isoform long is predominant in testis and kidney and isoform short is predominant in the spleen.
Similarity
belongs to the carbohydrate kinase pfkb family.

8. FRONT BACK

9. ATP binding site
ADO binding site

10. ATP binding site
ADO binding site

11. Topology diagram of AK. The -helices (labeled 1- 12) and the -strands (labeled 1- 14).

12. ADO binding site

13. ADO binding site

14. ATP binding site

15. ATP binding site

16. Stereodrawing of the adenosine 1 binding site.
W:water(no tryptophan in here) , F:Phe, T:Thr, Q:Gln, D:Asp, N:Asn, G:Gly

17. (b) Stereodrawing of the adenosine 2 binding site.
W:water(no tryptophan in here) , T:Thr, Q:Gln, D:Asp, G:Gly, H:His

18. Stereodiagram showing key active site residues and modeled (a) ATP and (b) Ap4A binding sites.

19. Stereodiagram showing key active site residues and modeled (a) ATP and (b) Ap4A binding sites.

21. References
1. Biochemistry, 37 (45), , 1998 Structure of Human Adenosine Kinase at 1.5 Å Resolution