Evidence for non‐cysteinyl coordination of the [2Fe‐2S] cluster in Escherichia coli succinate dehydrogenase

FEBS Letters

Cecchini, Gary¹  Johnson, Michael K.²  Sices, Harry¹  Schröder, Imke²  Werth, Mark T.³  Gunsalus, Robert P.²  Lasage, Susanne² 

[1] Molecular Biology Division, Veterans Administration Medical Center, San Francisco, CA 94121, USA;Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143, USA;Department of Chemistry and Center for Metalloenzyme Studies, University of Georgia, Athens, GA 30602, USA

关键词: Site-directed mutagenesis;    [2Fe-2S] cluster;    EPR;    Fumarate reductase;    Succinate dehydrogenase;    BVred;    reduced benzyl viologen;    MQH2;    menaquinol-6;    PMS;    phenazine methosulfate;   

DOI  :  10.1016/0014-5793(92)80086-V

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The consequences of replacing Cys⁶⁵ 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 FrdBCys⁶⁵Asp 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 FrdBCys⁶⁵Ala 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.

【 授权许可】

Unknown