Identification of rate-limiting steps in yeast heme biosynthesis.
The heme biosynthesis pathway in the yeast Saccharomyces cerevisiae is a highly regulated system, but the mechanisms accounting for this regulation remain unknown. In an attempt to identify rate-limiting steps in heme synthesis, which may constitute potential regulatory points, we constructed yeast strains overproducing two enzymes of the pathway: the porphobilinogen synthase (PBG-S) and deaminase (PBG-D). Biochemical analysis of the enzyme-overproducing strains revealed intracellular porphobilinogen and porphyrin accumulation. These results indicate that both enzymes play a rate-limiting role in yeast heme biosynthesis.
Hoffman
Marta
M
Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5A, 02-106 Warsaw, Poland.
Góra
Monika
M
Rytka
Joanna
J
D001483:Base Sequence; D015153:Blotting, Western; D017931:DNA Primers; D006418:Heme / Q000096:biosynthesis*; D011163:Hydroxymethylbilane Synthase / Q000378:metabolism; D007700:Kinetics; D000623:Porphobilinogen Synthase / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000378:metabolism*; D014575:Uroporphyrinogen Decarboxylase / Q000378:metabolism
D017931:DNA Primers; D006418:Heme; D011163:Hydroxymethylbilane Synthase; D014575:Uroporphyrinogen Decarboxylase; D000623:Porphobilinogen Synthase