Biosynthesis of hydroxymethylpyrimidine pyrophosphate in Saccharomyces cerevisiae

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 cont...

Full description

Saved in:
Bibliographic Details
Published in:Current genetics 2005-03, Vol.47 (3), p.156-162
Main Authors: Kawasaki, Yuko, Onozuka, Mari, Mizote, Tomoko, Nosaka, Kazuto
Format: Article
Language:English
Subjects:
Bacteria
Biosynthesis
E coli
Phosphotransferases (Phosphate Group Acceptor) - genetics
Phosphotransferases (Phosphate Group Acceptor) - metabolism
Proteins
Pyrimidines - biosynthesis
Saccharomyces cerevisiae - enzymology
Saccharomyces cerevisiae - genetics
Saccharomyces cerevisiae Proteins - genetics
Saccharomyces cerevisiae Proteins - metabolism
Thiamine Pyrophosphate - biosynthesis
Yeast
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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.
ISSN:0172-8083
1432-0983
DOI:10.1007/s00294-004-0557-x