We present a novel crystal structure of the IlvD/EDD family enzyme, l-arabinonate dehydratase from Rhizobium leguminosarum bv. trifolii (RlArDHT, EC 4.2.1.25), which catalyzes the conversion of l-arabinonate to 2-dehydro-3-deoxy-l-arabinonate. The enzyme is a tetramer consisting of a dimer of dimers, where each monomer is composed of two domains. The active site contains a catalytically important [2Fe-2S] cluster and Mg ion and is buried between two domains, and also at the dimer interface. The active site Lys129 was found to be carbamylated. Ser480 and Thr482 were shown to be essential residues for catalysis, and the S480A mutant structure showed an unexpected open conformation in which the active site was more accessible for the substrate. This structure showed the partial binding of l-arabinonate, which allowed us to suggest that the alkoxide ion form of the Ser480 side chain functions as a base and the [2Fe-2S] cluster functions as a Lewis acid in the elimination reaction.
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http://dx.doi.org/10.1021/acschembio.7b00304 | DOI Listing |
J Biol Chem
December 2024
Institut für Zytobiologie im Zentrum für Synthetische Mikrobiologie SynMikro, Philipps-Universität Marburg, Karl-von-Frisch-Str. 14, 35032 Marburg, Germany. Electronic address:
Mitochondria synthesize only a small set of their proteins on endogenous mitoribosomes. These particles differ in structure and composition from both their bacterial 70S ancestors and cytosolic 80S ribosomes. Recently published high resolution structures of the human mitoribosome revealed the presence of three [2Fe-2S] clusters in the small and large subunits.
View Article and Find Full Text PDFNat 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 PDFFront Pharmacol
November 2024
Department of Pharmacy, The Affiliated Hospital of Putian University, Putian, Fujian Province, China.
Background: CDGSH iron-sulfur domain 2 (CISD2), an iron-sulfur protein with a [2Fe-2S] cluster, plays a pivotal role in the progression of various cancers, including Diffuse Large B-cell Lymphoma (DLBCL). However, the mechanisms by which CISD2 regulates the occurrence and development of DLBCL remain to be fully elucidated.
Methods: The potential role of CISD2 as a predictive marker in DLBCL patients treated with the R-CHOP regimen was investigated through bioinformatics analysis and clinical cohort studies.
J Chem Theory Comput
December 2024
Advanced Computing, Mathematics and Data Division, Pacific Northwest National Laboratory, P.O. Box 999, MS J7-10, Richland, Washington 99352, United States.
Iron-sulfur clusters are crucial for biological electron transport and catalysis. Obtaining accurate geometries, energetics, manifolds of their excited electronic states, and reduction energies is important to understand their role in these processes. Using a [2Fe-2S] model complex with Fe and Fe oxidation states, which leads to different charges, i.
View Article and Find Full Text PDFJ Biol Chem
October 2024
Biosciences Center, National Renewable Energy Lab, Golden, Colorado, USA. Electronic address:
The HoxEFUYH complex of Synechocystis PCC 6803 (S. 6803) consists of a HoxEFU ferredoxin:NAD(P)H oxidoreductase subcomplex and a HoxYH [NiFe]-hydrogenase subcomplex that catalyzes reversible H oxidation. Prior studies have suggested that the presence of HoxE is required for reactivity with ferredoxin; however, it is unknown how HoxE is functionally integrated into the electron transfer network of the HoxEFU:ferredoxin complex.
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