5nq6
Crystal structure of the inhibited form of the redox-sensitive SufE-like sulfur acceptor CsdE from Escherichia coli at 2.40 Angstrom ResolutionCrystal structure of the inhibited form of the redox-sensitive SufE-like sulfur acceptor CsdE from Escherichia coli at 2.40 Angstrom Resolution
Structural highlights
FunctionCSDE_ECOLI Stimulates the cysteine desulfurase activity of CsdA. Contains a cysteine residue (Cys-61) that acts to accept sulfur liberated via the desulfurase activity of CsdA. May be able to transfer sulfur to TcdA/CsdL. Seems to support the function of TcdA in the generation of cyclic threonylcarbamoyladenosine at position 37 (ct(6)A37) in tRNAs that read codons beginning with adenine. Does not appear to participate in Fe/S biogenesis.[1] [2] [3] Publication Abstract from PubMedSulfur trafficking in living organisms relies on transpersulfuration reactions consisting in the enzyme-catalyzed transfer of S atoms via activated persulfidic S across protein-protein interfaces. The recent elucidation of the mechanistic basis for transpersulfuration in the CsdA-CsdE model system has paved the way for a better understanding of its role under oxidative stress. Herein we present the crystal structure of the oxidized, inactivated CsdE dimer at 2.4 A resolution. The structure sheds light into the activation of the Cys61 nucleophile on its way from a solvent-secluded position in free CsdE to a fully extended conformation in the persulfurated CsdA-CsdE complex. Molecular dynamics simulations of available CsdE structures allow to delineate the sequence of conformational changes underwent by CsdE and to pinpoint the key role played by the deprotonation of the Cys61 thiol. The low-energy subunit orientation in the disulfide-bridged CsdE dimer demonstrates the likely physiologic relevance of this oxidative dead-end form of CsdE, suggesting that CsdE could act as a redox sensor in vivo. Insights into the inhibited form of the redox-sensitive SufE-like sulfur acceptor CsdE.,Pena-Soler E, Aranda J, Lopez-Estepa M, Gomez S, Garces F, Coll M, Fernandez FJ, Tunon I, Vega MC PLoS One. 2017 Oct 18;12(10):e0186286. doi: 10.1371/journal.pone.0186286., eCollection 2017. PMID:29045454[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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