The E. coli SufS-SufE sulfur transfer system is more resistant to oxidative stress than IscS-IscU.
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.
Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, United States.
Yuyuan
Y
Dai
F Wayne
FW
Outten
D055162:Biocatalysis / Q000187:drug effects; D013437:Carbon-Sulfur Lyases / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D003545:Cysteine / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007506:Iron-Sulfur Proteins / Q000235:genetics / Q000378:metabolism*; D007700:Kinetics; D008190:Lyases / Q000235:genetics / Q000378:metabolism*; D013058:Mass Spectrometry; D016877:Oxidants / Q000494:pharmacology; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D013379:Substrate Specificity; D013455:Sulfur / Q000378:metabolism*
D002352:Carrier Proteins; D029968:Escherichia coli Proteins; D007506:Iron-Sulfur Proteins; C411665:IscU protein, E coli; D016877:Oxidants; C503794:Suf E protein, E coli; D013455:Sulfur; D006861:Hydrogen Peroxide; D008190:Lyases; D013437:Carbon-Sulfur Lyases; C080546:cysteine desulfurase; C034278:selenocysteine lyase; D003545:Cysteine