The yeast multicopper oxidase Fet3p and the iron permease Ftr1p physically interact.
High affinity iron uptake in yeast is carried out by a multicomponent system formed by the ferroxidase Fet3p and the iron permease Ftr1p. The currently accepted model predicts that Fet3p and Ftr1p are functionally associated, however, a structural interaction between these two proteins has not been proven yet. The methylotrophic yeast Pichia pastoris has been used to perform cross-linking studies aimed to demonstrate the existence of a Fet3p-Ftr1p complex. Cross-linking of membrane suspensions with the membrane-impermeable reagents DTSSP and BS(3) has evidenced the presence of a high molecular weight band with Fet3p oxidase activity. This band has been purified and subjected to N-terminal sequence analysis. Two sequences were found in the cross-linked species, one of which could be assigned to Fet3p and the other to Ftr1p. This is the first experimental demonstration that Fet3p and Ftr1p are physically associated.
Bonaccorsi di Patti
M Carmela
MC
Department of Biochemical Sciences A. Rossi Fanelli, University of Rome La Sapienza, Piazzale Aldo Moro 5, 00185 Rome, Italy. mariacarmela.bonaccorsi@uniroma l.it
Miele
Rossella
R
Eugenia Schininà
M
M
Barra
Donatella
D
D000595:Amino Acid Sequence; D001665:Binding Sites; D027682:Cation Transport Proteins / Q000737:chemistry* / Q000378:metabolism*; D002570:Ceruloplasmin / Q000737:chemistry* / Q000378:metabolism*; D004789:Enzyme Activation; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000737:chemistry / Q000378:metabolism; D010843:Pichia / Q000201:enzymology*; D011485:Protein Binding; D025941:Protein Interaction Mapping; D017386:Sequence Homology, Amino Acid
D027682:Cation Transport Proteins; D009097:Multienzyme Complexes; D002570:Ceruloplasmin