Cloning and characteristics of a positive regulatory gene, THI2 (PHO6), of thiamin biosynthesis in Saccharomyces cerevisiae.
A thi2(pho6) mutant of Saccharomyces cerevisiae, defective in the expression of structural genes for thiamin-repressible acid phosphatase and enzymes involved in thiamin biosynthesis, was found to retain sufficient thiamin transport activity. The transport activity was repressed by thiamin in growth medium. We isolated from a S. cerevisiae genomic library two hybrid plasmids, pTSR1 and pTSR2, containing 10.2- and 12.0-kilobase (kb) DNA fragments, respectively, which complement the thi2(pho6) mutation of S. cerevisiae. This gene was localized on a 6.0-kb ClaI-ClaI fragment in the subclone pTSR3. Complementation of the enzyme activities for thiamin metabolism in the thi2(pho6) mutant transformed by some plasmids with the TH12(PHO6) gene was also examined.
Nishimura
H
H
Department of Biochemistry, Kyoto Prefectural University of Medicine, Japan.
Kawasaki
Y
Y
Kaneko
Y
Y
Nosaka
K
K
Iwashima
A
A
D003001:Cloning, Molecular; D004271:DNA, Fungal / Q000235:genetics; D005800:Genes, Fungal; D005809:Genes, Regulator; D009154:Mutation; D010957:Plasmids; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D013831:Thiamine / Q000096:biosynthesis*; D014170:Transformation, Genetic
D004271:DNA, Fungal; D013831:Thiamine