The FET3 gene of S. cerevisiae encodes a multicopper oxidase required for ferrous iron uptake.
S. cerevisiae accumulate iron by a process requiring a ferrireductase and a ferrous transporter. We have isolated a mutant, fet3, defective for high affinity Fe(II) uptake. The wild-type FET3 gene was isolated by complementation of the mutant defect. Sequence analysis of the gene revealed the presence of an open reading frame coding for a protein with strong similarity to the family of blue multicopper oxidoreductases. Consistent with the role of copper in iron transport, growth of wild-type cells in copper-deficient media resulted in decreased ferrous iron transport. Addition of copper, but not other transition metals (manganese or zinc), to the assay media resulted in the recovery of Fe(II) transporter activity. We suggest that the catalytic activity of the Fet3 protein is required for cellular iron accumulation.
Askwith
C
C
Department of Pathology, University of Utah College of Medicine, Salt Lake City 84132.
Eide
D
D
Van Ho
A
A
Bernard
P S
PS
Li
L
L
Davis-Kaplan
S
S
Sipe
D M
DM
Kaplan
J
J
D000595:Amino Acid Sequence; D001693:Biological Transport, Active; D002570:Ceruloplasmin; D003001:Cloning, Molecular; D005296:Ferrous Compounds / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D005816:Genetic Complementation Test; D007501:Iron / Q000378:metabolism*; D008667:Metalloproteins / Q000737:chemistry; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D010088:Oxidoreductases / Q000235:genetics* / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
D005296:Ferrous Compounds; D008667:Metalloproteins; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; D007501:Iron; D010088:Oxidoreductases; C024748:copper oxidase; D002570:Ceruloplasmin; C085513:FET3 protein, S cerevisiae