title: Binding of Nitric Oxide in CDGSH-type [2Fe-2S] Clusters of the Human Mitochondrial Protein Miner2.
abstract: Iron-sulfur proteins are among the primary targets of nitric oxide in cells. Previous studies have shown that iron-sulfur clusters hosted by cysteine residues in proteins are readily disrupted by nitric oxide forming a protein-bound dinitrosyl iron complex, thiolate-bridged di-iron tetranitrosyl complex, or octanitrosyl cluster. Here we report that human mitochondrial protein Miner2 [2Fe-2S] clusters can bind nitric oxide without disruption of the clusters. Miner2 is a member of a new CDGSH iron-sulfur protein family that also includes two mitochondrial proteins: the type II diabetes-related mitoNEET and the Wolfram syndrome 2-linked Miner1. Miner2 contains two CDGSH motifs, and each CDGSH motif hosts a [2Fe-2S] cluster via three cysteine and one histidine residues. Binding of nitric oxide in the reduced Miner2 [2Fe-2S] clusters produces a major absorption peak at 422 nm without releasing iron or sulfide from the clusters. The EPR measurements and mass spectrometry analyses further reveal that nitric oxide binds to the reduced [2Fe-2S] clusters in Miner2, with each cluster binding one nitric oxide. Although the [2Fe-2S] cluster in purified human mitoNEET and Miner1 fails to bind nitric oxide, a single mutation of Asp-96 to Val in mitoNEET or Asp-123 to Val in Miner1 facilitates nitric oxide binding in the [2Fe-2S] cluster, indicating that a subtle change of protein structure may switch mitoNEET and Miner1 to bind nitric oxide. The results suggest that binding of nitric oxide in the CDGSH-type [2Fe-2S] clusters in mitochondrial protein Miner2 may represent a new nitric oxide signaling mode in cells.
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803.
authors.forename: Zishuo
authors.initials: Z
authors.lastname: Cheng
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803.
authors.forename: Aaron P
authors.initials: AP
authors.lastname: Landry
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803.
authors.forename: Yiming
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803. Electronic address: hding@lsu.edu.
authors.forename: Huangen
authors.initials: H
authors.lastname: Ding
mesh_terms: D006801:Humans; D007506:Iron-Sulfur Proteins / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D011485:Protein Binding; D015398:Signal Transduction
chemical_list: C525595:CISD1 protein, human; C523851:CISD2 protein, human; C000620502:CISD3 protein, human; D007506:Iron-Sulfur Proteins; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D009569:Nitric Oxide
keywords: EPR; Miner2; iron-sulfur protein; mitoNEET; mitochondria; mitochondrial disease; mitochondrial metabolism; nitric oxide