X-ray analysis of azido-thymidine diphosphate binding to nucleoside diphosphate kinase.Xu, Y., Sellam, O., Morera, S., Sarfati, S., Biondi, R., Veron, M., Janin, J.
(1997) Proc.Natl.Acad.Sci.USA 94: 7162-7165
- PubMed: 9207061
- PubMed Abstract:
- Adenosine 5'-Diphosphate Binding and the Active Site of Nucleoside Diphosphate Kinase
Morera, S.,Lascu, I.,Dumas, C.,Lebras, G.,Briozzo, P.,Veron, M.,Janin, J.
(1994) Biochemistry 33: 459
- Mechanism of Phosphate Transfer by Nucleoside Diphosphate Kinase: X-Ray Structures of the Phosphohistidine Intermediate of the Enzymes from Drosophila and Dictyostelium
Morera, S.,Chiadmi, M.,Lebras, G.,Lascu, I.,Janin, J.
(1995) Biochemistry 34: 11062
To be effective as antiviral agent, AZT (3'-azido-3'-deoxythymidine) must be converted to a triphosphate derivative by cellular kinases. The conversion is inefficient and, to understand why AZT diphosphate is a poor substrate of nucleoside diphosphat ...
To be effective as antiviral agent, AZT (3'-azido-3'-deoxythymidine) must be converted to a triphosphate derivative by cellular kinases. The conversion is inefficient and, to understand why AZT diphosphate is a poor substrate of nucleoside diphosphate (NDP) kinase, we determined a 2.3-A x-ray structure of a complex with the N119A point mutant of Dictyostelium NDP kinase. It shows that the analog binds at the same site and, except for the sugar ring pucker which is different, binds in the same way as the natural substrate thymidine diphosphate. However, the azido group that replaces the 3'OH of the deoxyribose in AZT displaces a lysine side chain involved in catalysis. Moreover, it is unable to make an internal hydrogen bond to the oxygen bridging the beta- and gamma-phosphate, which plays an important part in phosphate transfer.
Laboratoire d'Enzymologie et de Biochimie Structurales, Unité Propre de Recherche 9063, Centre National de la Recherche Scientifique, 91198 Gif-sur-Yvette, France.