Current Genetics

, Volume 47, Issue 3, pp 156–162

Biosynthesis of hydroxymethylpyrimidine pyrophosphate in Saccharomyces cerevisiae

  • Yuko Kawasaki
  • Mari Onozuka
  • Tomoko Mizote
  • Kazuto Nosaka
Research Article

DOI: 10.1007/s00294-004-0557-x

Cite this article as:
Kawasaki, Y., Onozuka, M., Mizote, T. et al. Curr Genet (2005) 47: 156. doi:10.1007/s00294-004-0557-x


Two redundant genes, THI20 and THI21, of Saccharomyces cerevisiae encode a 2-methyl-4-amino-5-hydroxymethylpyrimidine monophosphate (HMP-P) kinase required for thiamin biosynthesis. Using functional complementation analysis with an Escherichia coli mutant strain and a defined biochemical system containing partially purified proteins for the reconstitution of thiamin monophosphate synthesis, we demonstrate that both Thi20p and Thi21p proteins also have HMP kinase activity. Although each isoform independently can synthesize HMP pyrophosphate (HMP-PP) from HMP, there is a marked difference in efficiency between the two proteins. The thi20 deletion strain grows at the same rate as the parental strain in minimal medium without thiamin, but its ability to synthesize HMP-PP from HMP is significantly decreased. We discuss the possibility that HMP is not involved in the pathway of de novo thiamin synthesis in S. cerevisiae.


Hydroxymethylpyrimidine kinase Thiamin biosynthesis Bifunctional enzyme Saccharomyces cerevisiae 

Copyright information

© Springer-Verlag 2004

Authors and Affiliations

  • Yuko Kawasaki
    • 1
  • Mari Onozuka
    • 2
  • Tomoko Mizote
    • 3
  • Kazuto Nosaka
    • 4
  1. 1.Department of Food MicrobiologyDoshisha Women’s CollegeKyotoJapan
  2. 2.Department of BiochemistryKyoto Prefectural University of MedicineKyotoJapan
  3. 3.Department of Food and NutritionYamaguchi Prefectural UniversityYamaguchiJapan
  4. 4.Department of ChemistryKyoto Prefectural University of MedicineKyotoJapan

Personalised recommendations