An Arabidopsis cytochrome b561 with trans-membrane ferrireductase capability.
Ascorbate-reducible cytochromes b561 (Cyts-b561) are a class of intrinsic trans-membrane proteins. Tonoplast Cyt-b561 (TCytb), one of the four Cyt-b561 isoforms in Arabidopsis was localized to the tonoplast. We demonstrate here that the optical spectra, EPR spectra and redox potentials of recombinant TCytb are similar to those of the well characterized bovine chromaffin granule Cyt-b561. We provide evidence for the reduction of ferric-chelates by the reduced TCytb. It is also shown that TCytb is capable of trans-membrane electron transport from intracellular ascorbate to extracellular ferric-chelates in yeast cells.
Bérczi
Alajos
A
Institute of Biophysics, Biological Research Center, Hungarian Academy of Sciences, PO Box 521, H-6701 Szeged, Hungary. berczi@brc.hu
Su
Dan
D
Asard
Han
H
D000818:Animals; D017360:Arabidopsis / Q000201:enzymology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002417:Cattle; D002614:Chelating Agents / Q000378:metabolism; D003573:Cytochrome b Group / Q000235:genetics / Q000378:metabolism*; D038181:FMN Reductase / Q000235:genetics / Q000378:metabolism*; D005292:Ferricyanides / Q000378:metabolism; D007501:Iron / Q000378:metabolism; D010084:Oxidation-Reduction; D012441:Saccharomyces cerevisiae / Q000235:genetics
D029681:Arabidopsis Proteins; D002614:Chelating Agents; D003573:Cytochrome b Group; D005292:Ferricyanides; C023646:cytochrome b561; D007501:Iron; D038181:FMN Reductase; C023903:ferric citrate iron reductase