7c8m › Citations

The Structure of the Dimeric State of IscU Harboring Two Adjacent [2Fe-2S] Clusters Provides Mechanistic Insights into Cluster Conversion to [4Fe-4S].

Kunichika K, Nakamura R, Fujishiro T, Takahashi Y
Biochemistry 60 1569-1572 (2021)
Cited: 9 times
EuropePMC logo PMID: 33938220

Abstract

IscU serves as a scaffold for the de novo assembly of a [2Fe-2S] cluster prior to its delivery to recipient protein. It has also been proposed that on one dimer of bacterial IscU, two [2Fe-2S] clusters can be converted into a single [4Fe-4S] cluster. However, lack of structural information about the dimeric state of IscU has hindered our understanding of the underlying mechanisms. In this study, we determine the X-ray crystal structure of IscU from the thermophilic archaeon Methanothrix thermoacetophila and demonstrate a dimer structure of IscU in which two [2Fe-2S] clusters are facing each other in close proximity at the dimer interface. Our structure also reveals for the first time that Asp40 serves as a fourth ligand to the [2Fe-2S] cluster with three Cys ligands in each monomer, consistent with previous spectroscopic data. We confirm by EPR spectroscopic analysis that in solution two adjacent [2Fe-2S] clusters in the wild-type dimer are converted to a [4Fe-4S] cluster via reductive coupling. Furthermore, we find that the H106A substitution abolishes the reductive conversion to the [4Fe-4S] cluster without structural alteration, suggesting that His106 is functionally involved in this process. Overall, these findings provide a structural explanation for the assembly and conversion of Fe-S clusters on IscU and highlight a dynamic process that advances via association and dissociation of the IscU dimer.

Articles - 7c8m mentioned but not cited (1)

  1. Analysis of insertions and extensions in the functional evolution of the ribonucleotide reductase family. Burnim AA, Xu D, Spence MA, Jackson CJ, Ando N. Protein Sci 31 e4483 (2022)


Reviews citing this publication (3)

  1. Molecular Details of the Frataxin-Scaffold Interaction during Mitochondrial Fe-S Cluster Assembly. Campbell CJ, Pall AE, Naik AR, Thompson LN, Stemmler TL. Int J Mol Sci 22 6006 (2021)
  2. Structural insights into auxiliary cofactor usage by radical S-adenosylmethionine enzymes. Jeyachandran VR, Boal AK. Curr Opin Chem Biol 68 102153 (2022)
  3. Interaction of client-the scaffold on which FeS clusters are build-with J-domain protein Hsc20 and its evolving Hsp70 partners. Marszalek J, Craig EA. Front Mol Biosci 9 1034453 (2022)

Articles citing this publication (5)

  1. N-terminal tyrosine of ISCU2 triggers [2Fe-2S] cluster synthesis by ISCU2 dimerization. Freibert SA, Boniecki MT, Stümpfig C, Schulz V, Krapoth N, Winge DR, Mühlenhoff U, Stehling O, Cygler M, Lill R. Nat Commun 12 6902 (2021)
  2. Iron Insertion at the Assembly Site of the ISCU Scaffold Protein Is a Conserved Process Initiating Fe-S Cluster Biosynthesis. Srour B, Gervason S, Hoock MH, Monfort B, Want K, Larkem D, Trabelsi N, Landrot G, Zitolo A, Fonda E, Etienne E, Gerbaud G, Müller CS, Oltmanns J, Gordon JB, Yadav V, Kleczewska M, Jelen M, Toledano MB, Dutkiewicz R, Goldberg DP, Schünemann V, Guigliarelli B, Burlat B, Sizun C, D'Autréaux B. J Am Chem Soc 144 17496-17515 (2022)
  3. Structural diversity of cysteine desulfurases involved in iron-sulfur cluster biosynthesis. Fujishiro T, Nakamura R, Kunichika K, Takahashi Y. Biophys Physicobiol 19 1-18 (2022)
  4. Protein interactions in the biological assembly of iron-sulfur clusters in Escherichia coli: Molecular and mechanistic aspects of the earliest assembly steps. Bonomi F, Iametti S, Barbiroli A. IUBMB Life 74 723-732 (2022)
  5. Class III hybrid cluster protein homodimeric architecture shows evolutionary relationship with Ni, Fe-carbon monoxide dehydrogenases. Fujishiro T, Takaoka K. Nat Commun 14 5609 (2023)


Quick links