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Evidence for non‐cysteinyl coordination of the [2Fe‐2S] cluster in Escherichia coli succinate dehydrogenase
Author(s) -
Werth Mark T.,
Sices Harry,
Cecchini Gary,
Schröder Imke,
Lasage Susanne,
Gunsalus Robert P.,
Johnson Michael K.
Publication year - 1992
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(92)80086-v
Subject(s) - succinate dehydrogenase , escherichia coli , fumarate reductase , enzyme , biochemistry , iron–sulfur cluster , chemistry , protein subunit , dehydrogenase , aspartic acid , mutant , cysteine , residue (chemistry) , ligand (biochemistry) , stereochemistry , amino acid , receptor , gene
The consequences of replacing Cys 65 in the FrdB subunit of Escherichia coli fumarate reductase by Asp or Ala have been investigated in terms of bacterial growth, enzymatic activity, and the EPR/redox properties of the [2Fe‐2S] cluster. An aspartic acid residue occupies the equivalent position in E. coli succinate dehydrogenase, and the FrdBCys 65 Asp mutation has little effect on cell growth, enzyme activity or the physical properties of the Frd [2Fe‐2S] cluster. In contrast, the [2Fe‐2S] cluster was not observed in the FrdBCys 65 Ala mutant showing that a coordinating residue is required at this position for assembly of this cluster and significant levels or enzymatic activity. These results support the presence of one non‐cysteinyl, oxygenic ligand for the [2Fe‐2S] cluster in E. coli succinate dehydrogenase.