High-affinity iron uptake by yeast cells appears to require the presence of a complex formed on the plasma membrane by the multicopper oxidase Fet3 and the permease Ftr1 which work together to allow iron to enter safely inside the cell. The Pichia pastoris ferroxidase Fet3 has been cloned and it has been found to display high sequence similarity to other yeast multicopper oxidases, including all the predicted ligands for the catalytic copper atoms and for the iron substrate. P. pastoris appears to possess a high-affinity iron uptake system similar to that of S. cerevisiae, as far as regulation of expression is concerned. However, the P. pastoris high-affinity iron up-take system presents a Km value for iron almost ten times higher than that of S. cerevisiae, possibly to control iron fluxes over a wider range of concentrations of this metal, in order to avoid toxic iron over-loading. © 2001 Academic Press.
Cloning of Pichia pastoris Fet3: Insights into the high affinity iron uptake system / Maria Paola, Paronetto; Miele, Rossella; Antonella, Maugliani; Borro, Marina; BONACCORSI DI PATTI, Maria Carmela. - In: ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS. - ISSN 0003-9861. - 392:1(2001), pp. 162-167. [10.1006/abbi.2001.2425]
Cloning of Pichia pastoris Fet3: Insights into the high affinity iron uptake system
MIELE, Rossella;BORRO, Marina;BONACCORSI DI PATTI, Maria Carmela
2001
Abstract
High-affinity iron uptake by yeast cells appears to require the presence of a complex formed on the plasma membrane by the multicopper oxidase Fet3 and the permease Ftr1 which work together to allow iron to enter safely inside the cell. The Pichia pastoris ferroxidase Fet3 has been cloned and it has been found to display high sequence similarity to other yeast multicopper oxidases, including all the predicted ligands for the catalytic copper atoms and for the iron substrate. P. pastoris appears to possess a high-affinity iron uptake system similar to that of S. cerevisiae, as far as regulation of expression is concerned. However, the P. pastoris high-affinity iron up-take system presents a Km value for iron almost ten times higher than that of S. cerevisiae, possibly to control iron fluxes over a wider range of concentrations of this metal, in order to avoid toxic iron over-loading. © 2001 Academic Press.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.