Mössbauer studies of Escherichia coli biotin synthase: evidence for reversible interconversion between [2Fe‐2S]2+ and [4Fe‐4S]2+ clusters

FEBS Letters

Trautwein, A.X²  Benda, R²  Florentin, D¹  Marquet, A¹  Tse Sum Bui, B¹ 

[1] Laboratoire de Chimie Organique et Biologique, Université Paris VI – CNRS UMR 7613, 4 place Jussieu, 75252 Paris Cedex 05, France;Institut für Physik, Medizinische Universität, Ratzeburger Allee 160, 23538 Lübeck, Germany

关键词: Biotin synthase;    Iron-sulfur cluster;    Mössbauer spectroscopy;    Fe-S;    iron-sulphur cluster;    AdoMet;    S-adenosylmethionine;    PFL;    pyruvate formate lysate;    ARNR;    anaerobic ribonucleotide reductase;    LAM;    lysine 2;    3-aminomutase;    EPR;    electron paramagnetic resonance;    VTMCD;    variable-temperature magnetic circular dichroism;    DTT;    dithiothreitol;    FNR;    fumarate nitrate reduction;   

DOI  :  10.1016/S0014-5793(99)01300-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The nature and properties of the iron-sulphur (Fe-S) cluster in as-prepared and reduced biotin synthase of Escherichia coli have been investigated by Mössbauer spectroscopy. Our data clearly demonstrate that in the as-prepared sample, the cluster is present as [2Fe-2S]²⁺ with isomer shift, δ=0.29 mm/s and quadrupole splitting, ΔE _Q=0.53 mm/s, indicating incomplete cysteinyl-S coordination. Anaerobic reduction by dithionite in the presence of 55% (v/v) glycerol converts this form to [4Fe-4S]²⁺ (δ=0.45 mm/s and ΔE _Q=1.11 mm/s) and is accompanied by some destruction to Fe²⁺. This cluster conversion is reversible and when exposed to air, the [4Fe-4S]²⁺ cluster is quantitatively reconverted to the [2Fe-2S]²⁺ cluster without any further cluster degradation.

【 授权许可】

Unknown