Mechanism and structural dynamics of sulfur transfer during de novo [2Fe-2S] cluster assembly on ISCU2.

Autor: Schulz V; Institut für Zytobiologie, Philipps-Universität Marburg, Karl-von-Frisch-Str. 14, 35032, Marburg, Germany.; Zentrum für Synthetische Mikrobiologie SynMikro, Karl-von-Frisch-Str. 14, 35032, Marburg, Germany., Steinhilper R; Redox and Metalloprotein Research Group, Max Planck Institute of Biophysics, Max-von-Laue-Str. 3, 60438, Frankfurt am Main, Germany., Oltmanns J; Department of Physics, Biophysics and Medical Physics, University of Kaiserslautern-Landau, Erwin-Schrödinger-Str. 46, 67663, Kaiserslautern, Germany., Freibert SA; Institut für Zytobiologie, Philipps-Universität Marburg, Karl-von-Frisch-Str. 14, 35032, Marburg, Germany.; Zentrum für Synthetische Mikrobiologie SynMikro, Karl-von-Frisch-Str. 14, 35032, Marburg, Germany.; Steinmühle-Schule & Internat, Steinmühlenweg 21, 35043, Marburg, Germany., Krapoth N; Institut für Zytobiologie, Philipps-Universität Marburg, Karl-von-Frisch-Str. 14, 35032, Marburg, Germany.; Zentrum für Synthetische Mikrobiologie SynMikro, Karl-von-Frisch-Str. 14, 35032, Marburg, Germany., Linne U; Mass Spectrometry Facility of the Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Str. 4, 35032, Marburg, Germany., Welsch S; Central Electron Microscopy Facility, Max Planck Institute of Biophysics, Max-von-Laue-Str. 3, 60438, Frankfurt am Main, Germany., Hoock MH; Department of Physics, Biophysics and Medical Physics, University of Kaiserslautern-Landau, Erwin-Schrödinger-Str. 46, 67663, Kaiserslautern, Germany., Schünemann V; Department of Physics, Biophysics and Medical Physics, University of Kaiserslautern-Landau, Erwin-Schrödinger-Str. 46, 67663, Kaiserslautern, Germany., Murphy BJ; Redox and Metalloprotein Research Group, Max Planck Institute of Biophysics, Max-von-Laue-Str. 3, 60438, Frankfurt am Main, Germany. bonnie.murphy@biophys.mpg.de., Lill R; Institut für Zytobiologie, Philipps-Universität Marburg, Karl-von-Frisch-Str. 14, 35032, Marburg, Germany. lill@staff.uni-marburg.de.; Zentrum für Synthetische Mikrobiologie SynMikro, Karl-von-Frisch-Str. 14, 35032, Marburg, Germany. lill@staff.uni-marburg.de.
Jazyk: angličtina
Zdroj: Nature communications [Nat Commun] 2024 Apr 16; Vol. 15 (1), pp. 3269. Date of Electronic Publication: 2024 Apr 16.
DOI: 10.1038/s41467-024-47310-8
Abstrakt: Maturation of iron-sulfur proteins in eukaryotes is initiated in mitochondria by the core iron-sulfur cluster assembly (ISC) complex, consisting of the cysteine desulfurase sub-complex NFS1-ISD11-ACP1, the scaffold protein ISCU2, the electron donor ferredoxin FDX2, and frataxin, a protein dysfunctional in Friedreich's ataxia. The core ISC complex synthesizes [2Fe-2S] clusters de novo from Fe and a persulfide (SSH) bound at conserved cluster assembly site residues. Here, we elucidate the poorly understood Fe-dependent mechanism of persulfide transfer from cysteine desulfurase NFS1 to ISCU2. High-resolution cryo-EM structures obtained from anaerobically prepared samples provide snapshots that both visualize different stages of persulfide transfer from Cys381 NFS1 to Cys138 ISCU2 and clarify the molecular role of frataxin in optimally positioning assembly site residues for fast sulfur transfer. Biochemical analyses assign ISCU2 residues essential for sulfur transfer, and reveal that Cys138 ISCU2 rapidly receives the persulfide without a detectable intermediate. Mössbauer spectroscopy assessing the Fe coordination of various sulfur transfer intermediates shows a dynamic equilibrium between pre- and post-sulfur-transfer states shifted by frataxin. Collectively, our study defines crucial mechanistic stages of physiological [2Fe-2S] cluster assembly and clarifies frataxin's molecular role in this fundamental process.
(© 2024. The Author(s).)
Databáze: MEDLINE
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