Your browser has javascript turned off or blocked. This will lead to some parts of our website to not work properly or at all. Turn on javascript for best performance.

The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here:

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

Default user image.

Ashfaq Ali


Default user image.

Two thymidine kinases and one multisubstrate deoxyribonucleoside kinase salvage DNA precursors in Arabidopsis thaliana.


  • Anders Ranegaard Clausen
  • Lenart Girandon
  • Ashfaq Ali
  • Wolfgang Knecht
  • Elzbieta Rozpedowska
  • Michael Sandrini
  • Erik Andreasson
  • Birgitte Munch-Petersen
  • Jure Piskur

Summary, in English

Deoxyribonucleotides are the building blocks of DNA and can be synthesized via de novo and salvage pathways. Deoxyribonucleoside kinases (dNKs) salvage deoxyribonucleosides by transfer of a phosphate group to the 5' of a deoxyribonucleoside. This salvage pathway is well characterized in mammals but in contrast little is known about how plants salvage deoxyribonucleosides. We show that during salvage, deoxyribonucleosides can be phosphorylated by extracts of Arabidopsis thaliana into corresponding mono-phosphate compounds with a surprising preference for purines over pyrimidines. Deoxyribonucleoside kinase activities were present in all tissues during all growth stages. In the A. thaliana genome we identified two types of genes that could encode enzymes which are involved in the salvage of deoxyribonucleosides. Thymidine kinase activity was encoded by two thymidine kinase 1-like genes (AtTK1a and AtTK1b) and deoxyadenosine, deoxyguanosine and deoxycytidine kinase activities were encoded by a single AtdNK gene. T-DNA insertion lines of AtTK1a and AtTK1b mutant genes had normal growth, but AtTK1a AtTK1b double mutants died at an early stage, which indicates that AtTK1a and AtTK1b catalyze redundant reactions. Our results point out a crucial role for salvage of thymidine during early plant development. © 2012 The Authors Journal compilation © 2012 FEBS.


  • Department of Biology
  • Molecular Cell Biology

Publishing year







The FEBS Journal





Document type

Journal article


Federation of European Neuroscience Societies and Blackwell Publishing Ltd


  • Biochemistry and Molecular Biology




  • ISSN: 1742-464X