TY - JOUR
T1 - A Seven‐iron Ferredoxin from the Thermoacidophilic Archaeon Desulfurolobus ambivalens
AU - Teixeira, Miguel
AU - Batista, Rita
AU - Campos, António P.
AU - Gomes, Cláudio
AU - Mendes, Joaquim
AU - Pacheco, Isabel
AU - Anemuller, Stefan
AU - Hagen, Wilfred R.
N1 - Copyright:
Copyright 2016 Elsevier B.V., All rights reserved.
PY - 1995/1
Y1 - 1995/1
N2 - A seven‐iron ferredoxin was isolated from aerobically grown cells of the hyperthermoacidophilic archaeon Desulfurolobus ambivalens (DSM 3772). The protein is monomeric, with an apparent molecular mass of 15 kDa and contains 7 iron atoms/molecule. The N‐terminal sequence shows a large similarity (70% identity) with that of the ferredoxin isolated from the archaeon Sulfolobus acidocaldarius. The EPR characteristics in both the native (oxidized) and dithionite‐reduced states of this protein allowed an unequivocal identification of a [3Fe‐4S]1+/0 center, with a reduction potential of −270 ± 20 mV, at pH 7.5. The protein also contains a [4Fe‐4S]2+/1+ center with a very low reduction potential (Eo = ‐540 mV, pH 7.0), which yields a rhombic EPR spectrum upon reduction with sodium dithionite at high pH. The reduction potentials of both centers are slightly pH dependent between pH 6 and 9. The [3Fe‐4S] ferredoxin center is able to accept electrons from pyruvate oxidase and NADH oxidase isolated from D. ambivalens. This ferredoxin is present in large amounts (at least 130 mg/kg wet cells), which allowed the unequivocal observation of oxidized [3Fe‐4S] clusters in intact D. ambivalens cells.
AB - A seven‐iron ferredoxin was isolated from aerobically grown cells of the hyperthermoacidophilic archaeon Desulfurolobus ambivalens (DSM 3772). The protein is monomeric, with an apparent molecular mass of 15 kDa and contains 7 iron atoms/molecule. The N‐terminal sequence shows a large similarity (70% identity) with that of the ferredoxin isolated from the archaeon Sulfolobus acidocaldarius. The EPR characteristics in both the native (oxidized) and dithionite‐reduced states of this protein allowed an unequivocal identification of a [3Fe‐4S]1+/0 center, with a reduction potential of −270 ± 20 mV, at pH 7.5. The protein also contains a [4Fe‐4S]2+/1+ center with a very low reduction potential (Eo = ‐540 mV, pH 7.0), which yields a rhombic EPR spectrum upon reduction with sodium dithionite at high pH. The reduction potentials of both centers are slightly pH dependent between pH 6 and 9. The [3Fe‐4S] ferredoxin center is able to accept electrons from pyruvate oxidase and NADH oxidase isolated from D. ambivalens. This ferredoxin is present in large amounts (at least 130 mg/kg wet cells), which allowed the unequivocal observation of oxidized [3Fe‐4S] clusters in intact D. ambivalens cells.
UR - http://www.scopus.com/inward/record.url?scp=0028895764&partnerID=8YFLogxK
U2 - 10.1111/j.1432-1033.1995.tb20392.x
DO - 10.1111/j.1432-1033.1995.tb20392.x
M3 - Journal articles
C2 - 7851403
AN - SCOPUS:0028895764
VL - 227
SP - 322
EP - 327
JO - European Journal of Biochemistry
JF - European Journal of Biochemistry
SN - 0014-2956
IS - 1-2
ER -