Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, United States.
FEBS Lett. 2012 Nov 16;586(22):4016-22. doi: 10.1016/j.febslet.2012.10.001. Epub 2012 Oct 12.
During oxidative stress in Escherichiacoli, the SufABCDSE stress response pathway mediates iron-sulfur (Fe-S) cluster biogenesis rather than the Isc pathway. To determine why the Suf pathway is favored under stress conditions, the stress response SufS-SufE sulfur transfer pathway and the basal housekeeping IscS-IscU pathway were directly compared. We found that SufS-SufE cysteine desulfurase activity is significantly higher than IscS-IscU at physiological cysteine concentrations and after exposure to H(2)O(2). Mass spectrometry analysis demonstrated that IscS-IscU is more susceptible than SufS-SufE to oxidative modification by H(2)O(2). These important results provide biochemical insight into the stress resistance of the Suf pathway.
在大肠杆菌的氧化应激中， SufABCDSE 应激反应途径介导铁硫 (Fe-S) 簇的生物发生，而不是 Isc 途径。为了确定为什么 Suf 途径在应激条件下更受青睐，直接比较了应激反应 SufS-SufE 硫转移途径和基础管家 IscS-IscU 途径。我们发现，在生理半胱氨酸浓度下和暴露于 H(2)O(2)后， SufS-SufE 半胱氨酸脱硫酶活性明显高于 IscS-IscU。质谱分析表明，IscS-IscU 比 SufS-SufE 更容易受到 H(2)O(2)的氧化修饰。这些重要的结果为 Suf 途径的应激抗性提供了生化见解。
