IscU is a central component of the ISC machinery and serves as a scaffold for the de novo assembly of iron-sulfur (Fe-S) clusters prior to their delivery to target apo-Fe-S proteins. However, the molecular mechanism is not yet fully understood. In this study, we have conducted mutational analysis of E. coli IscU using the recently developed genetic complementation system of a mutant that can survive without Fe-S clusters. The Fe-S cluster ligands (C37, C63, H105, C106) and the proximal D39 and K103 residues are essential for in vivo function of IscU and could not be substituted with any other amino acids. Furthermore, we found that substitution of Y3, a strictly conserved residue among IscU homologs, abolished in vivo functions. Surprisingly, a second-site suppressor mutation in IscS (A349V) reverted the defect caused by IscU Y3 substitutions. Biochemical analysis revealed that IscU Y3 was crucial for functional interaction with IscS and sulfur transfer between the two proteins. Our findings suggest that the critical role of IscU Y3 is linked to the conformational dynamics of the flexible loop of IscS, which is required for the ingenious sulfur transfer to IscU.
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http://dx.doi.org/10.1111/mmi.14392 | DOI Listing |
Comput Methods Biomech Biomed Engin
December 2024
Department of Hepatobiliary Surgery, Quzhou Hospital Affiliated of Wenzhou Medical University (Quzhou People's Hospital), Quzhou, Zhejiang, China.
Background: The prognosis of cancers is strongly connected with nitrogen metabolism (NM), which plays a critical role in the microenvironment and growth of tumors. It is unsubstantiated, however, how important NM-related genes are for the prognosis of hepatocellular carcinoma (HCC).
Methods: Using publicly available data, we examined potential mechanisms of NM-related genes in HCC, created a predictive model, and assessed immune infiltration and medication sensitivity.
Nat Commun
December 2024
Redox and Metalloprotein Research Group, Max Planck Institute of Biophysics, Max-von-Laue-Str. 3, 60438, Frankfurt am Main, Germany.
Iron-sulfur (FeS) protein biogenesis in eukaryotes begins with the de novo assembly of [2Fe-2S] clusters by the mitochondrial core iron-sulfur cluster assembly (ISC) complex. This complex comprises the scaffold protein ISCU2, the cysteine desulfurase subcomplex NFS1-ISD11-ACP1, the allosteric activator frataxin (FXN) and the electron donor ferredoxin-2 (FDX2). The structural interaction of FDX2 with the complex remains unclear.
View Article and Find Full Text PDFAnticancer Res
November 2024
Department of Gastroenterological Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan.
J Biol Chem
November 2024
Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Madrid, Spain; Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, Madrid, Spain. Electronic address:
Medicine (Baltimore)
October 2024
Urology Department, First Hospital of Jilin University, Changchun, Jilin Province, China.
Ferroptosis is iron-dependent programmed cell death that inhibits tumor growth, particularly in traditional treatment-resistant tumors. Prognostic models constructed from ferroptosis-related genes are lacking; prognostic biomarkers remain insufficient. We acquired gene expression data and corresponding clinical information for bladder cancer (BC) samples from public databases.
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