A stable intermediate product of the archaeal zinc-containing 7Fe ferredoxin from Sulfolobus sp. strain 7 by artificial oxidative conversion

FEBS Lett. 1997 Nov 10;417(2):223-6. doi: 10.1016/s0014-5793(97)01286-6.


Irreversible conversion of the purified zinc-containing 7Fe ferredoxin from the thermoacidophilic archaeon Sulfolobus sp. strain 7 was found to occur under aerobic conditions at pH 5.0 and at 4 degrees C. This process accompanied a substantial increase of the electron paramagnetic resonance signal attributed to a [3Fe-4S]1+ cluster, and the converted form containing approximately 6 Fe/Zn (mol/mol) had a net charge different from that of the native 7Fe ferredoxin. These data provide evidence for the formation of a stable intermediate product of the archaeal ferredoxin having two [3Fe-4S] clusters and a zinc center by artificial oxidative degradation. This further explains the discrepancy that a zinc center and two [3Fe-4S] clusters (but not a zinc center and one [3Fe-4S] cluster plus one [4Fe-4S] cluster) are observed in the crystal structure at pH 5.0.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aerobiosis
  • Electron Spin Resonance Spectroscopy
  • Electrophoresis, Polyacrylamide Gel
  • Ferredoxins / chemistry*
  • Hydrogen-Ion Concentration
  • Iron / chemistry
  • Iron-Sulfur Proteins / chemistry
  • Molecular Weight
  • Oxidation-Reduction
  • Sulfolobus / chemistry*
  • Zinc / chemistry


  • Ferredoxins
  • Iron-Sulfur Proteins
  • Iron
  • Zinc